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A Rational Approach to Sentencing Offenders for Animal Cruelty: A Normative and Scientific Analysis Underpinning Proportionate Penalties for Animal Cruelty Offenders

Mirko Bagaric,[1]* Jane Kotzmann[2]** & Gabrielle Wolf[3]***


In the past few decades, concern for animals has grown, particularly due to increased interest in the ethics and practice of veganism. Nevertheless, humans continue to inflict senseless suffering on animals, and the law regarding the manner in which we deal with animal cruelty offenders remains in a rudimentary state. The United States has been slow to criminalize comprehensively and penalize fittingly human cruelty towards animals. This is attributable to the lack of consistent, broad definitions of animal cruelty, and established, considered jurisprudence regarding the objectives, principles, and other matters that should inform the sentencing of animal cruelty offenders. As a consequence, such offenders can receive varied penalties for the same crimes in different jurisdictions, and some of those sanctions are unduly lenient, while others are unduly harsh. These outcomes are unacceptable given the widespread suffering experienced by animals at the hands of humans, and the importance of coherent criminal law and sentencing practice, which is the domain where society (through the courts) acts in its most coercive manner against individuals. This Article addresses these shortcomings and furthers current federal law by advancing a model approach to the criminalization of cruelty towards animals and sentencing of animal cruelty offenders, which we argue should apply in all American jurisdictions.

Unlike the recently enacted Preventing Animal Cruelty and Torture Act (PACT) Act, we propose the development of a classification of animal cruelty offenses that differentiates between animals on the basis of their sentience. As there are many different animals, it is not tenable to particularize criminal law and sentencing practice in relation to each species. Nevertheless, scientific investigation has established that vertebrates (animals with a spine)[4] have greater sentience (ability to perceive through their senses)[5] and greater capacity to feel pain than other animals.[6] Thus, in accordance with the principle of proportionality,[7] we argue that it is important to treat offenses against vertebrates as especially warranting censure and punishment. We also suggest broadening current definitions of animal cruelty and removing exclusions of certain acts from them in order to encapsulate the varied nature and context of such offending. In particular, we consider that definitions of animal cruelty should include, in addition to cruelty towards companion animals (who generally enjoy higher levels of legal protection than other animals), cruelty towards animals that people use for food, clothing, research, sport and entertainment, and animals that live in the wild. Further, “human-use typologies” (the ways in which humans use animals)[8] are irrelevant and therefore, should not be relied upon to determine whether an offense of animal cruelty has occurred.

At present, sentencing law regarding animal cruelty offenses is flawed because it strives to achieve the objectives of general deterrence and specific deterrence.[9] Research demonstrates that increases to the harshness of sanctions do not correlate with lower rates of commission of crime and recidivism.[10] Rehabilitation is another objective of sentencing law.[11] If animal cruelty offenders demonstrate good prospects of reform, we consider that this could be a mitigating factor in sentencing them. Community protection is also currently an objective of sentencing law.[12] We recommend that, in sentencing animal cruelty offenders, community protection remain a relevant consideration, particularly because cruelty towards animals can precede and co-occur with the commission of offenses against humans.[13] Above all, however, we propose that the chief determinant of penalties for animal cruelty offenses should be the principle of proportionality, which provides that the harshness of the sanction should match the seriousness of the offense.[14]

In discussing the application of the principle of proportionality, we consider whether the death of an animal because of a human act of cruelty should aggravate the gravity of the offense. This would certainly be the case if an offender murdered a person, but there is potentially a significant difference between offenses committed against at least some animals and those committed against humans. While humans generally exhibit an understanding of their ongoing existence and concept of the future, not all animals do so. We nonetheless consider that if scientific evidence indicates that an animal is aware of its ongoing existence and has a clear preference for remaining alive, causing the death of that animal through an act of cruelty could be a factor that increases the severity of the offense.[15] This is because the animal will have lost its expectation of future life. In addition, we maintain that the death of an animal through an act of cruelty would make the crime more serious where it causes distress to a human (most typically where the animal is a person’s pet) or suffering of another animal, one that depended on the killed animal (for example, where the animal that is killed was nurturing its offspring).

More broadly, we propose that three matters in particular should inform the classification of animal cruelty offenses and the sentencing of them. These matters are science, social norms, and moral theory. First, we consider that scientific evidence about animals’ capacity to feel pain and suffer should influence the law regarding animal cruelty offending for the reason that it can indicate the impact on animals of different forms of human cruelty. We now know that many vertebrates feel physical pain that is the same as that experienced by humans and prefer to avoid it.[16] Cruelty towards vertebrates, therefore, should be sanctioned more heavily than cruelty towards animals that lack receptors to register pain. It is also clear that some animals are able to suffer psychological harm.[17] Accordingly, such pain should also influence the law relating to animal cruelty offenses. The extent of pain that scientific investigation indicates animals experience as a consequence of human cruelty can inform the application of the principle of proportionality in determining an appropriate penalty for this offending.

Second, scientific evidence regarding animals’ capacity to feel pain will most probably in time (if it has not already) inform social norms regarding the appropriate treatment of animals. We maintain in this Article that, given the strong connection between criminal law and normative values,[18] it is vital that the latter, where they pertain to human interaction with animals generally, are taken into account in the classification and sentencing of animal cruelty offenses. The law concerning animal cruelty offending will garner respect and retain legitimacy only if it reflects, at least to some degree, current, accepted attitudes regarding the ways in which humans relate to animals. A key contemporary normative principle that we argue must inform the law is that humans should not cause animals to unduly suffer pain.

Third, morality shapes social norms, and therefore, the law.[19] In this Article, we demonstrate that the application of the two major streams of moral theories—consequentialist and non-consequentialist—establishes that many animals have what is described in philosophy as “moral status” or “moral standing.” As a consequence, it is ethically imperative that we take those animals’ interests into account in our decision-making about whether human behavior towards them is morally right or wrong. Notwithstanding differences between them, these moral theories justify according legal protection to animals that have moral standing through how we define animal cruelty offenses and sentence those who breach them.

In this Article, we demonstrate that the above proposal would remedy current problems with the law concerning animal cruelty offending. In particular, it would lead to more coherent and consistent categorization of these offenses and sentencing of offenders. If the main consideration that informs this area of the law is the principle of justice that the punishment should match the crime, it will better reflect normative standards and often result in the imposition of harsher sentences on animal cruelty offenders.

In the next part of the Article, we explain the current law regarding animal cruelty offenses, and sentencing law and practice in relation to offenders who breach it in the United States. This is followed in Part II by a discussion of the objectives and principles that at present do, and those that we argue should, inform the sentencing of animal cruelty offenders. In Part III, we examine other matters that we consider should influence the classification of animal cruelty offenses and sentencing of them, namely: scientific research concerning animals’ capacity to feel pain; social norms regarding human interaction with animals; and moral theories that justify ascribing moral status. The reform recommendations are detailed in Part IV and are summarized in the concluding remarks.

The Current Law Regarding Animal Cruelty Offenses and Sentencing of Them in the United States

Overview of Sentencing Law and Practice

Prior to examining animal cruelty crimes and the manner in which offenders are currently sentenced for them, we provide an overview of the framework of sentencing law. This helps to explain the approach to the sentencing of animal cruelty offenders at present and the context for the reform proposals advanced in this Article.

Each jurisdiction in the United States has its own sentencing law.[20] However, several key similarities underpin sentencing in all the jurisdictions. In particular, there is a commonality regarding the key sentencing objectives, namely, community protection, general and specific deterrence, rehabilitation, and retribution.[21] These (frequently competing) objectives are given effect through sanctions imposed on offenders and the nature of the sanction is often informed by prescriptive pre-determined penalties set out in penalty grids.[22] Typically, most jurisdictions implement the sentencing approach that was adopted at the federal level.

The Federal Sentencing Guidelines exemplify prescribed penalty laws and sentencing guidelines that are a defining feature of American sentencing law. The Federal Sentencing Guidelines have been analyzed more than any other prescribed penalty system in the United States.[23] They are also important because they have significantly influenced sentencing at the state level, and of course, have had an impact on the many offenders who have been sentenced under them.[24] Moreover, application of them has resulted in a growth in incarceration levels.[25] Melissa Hamilton notes that the “federal government now operates the single largest criminal justice system by inmate count in the United States. Indeed, the federal prison system itself is among the top ten largest by country in the world.”[26] In addition, it has been acknowledged that:

[H]istory proves that decisions made in Washington affect the whole criminal justice system, for better or worse. Federal funding drives state policy, and helped create our current crisis of mass incarceration. And the federal government sets the national tone, which is critical to increasing public support and national momentum for change. Without a strong national movement, the bold reforms needed at the state and local level cannot emerge.[27]

The Federal Sentencing Guidelines are similar to other grid sentencing systems in that an offender’s prior convictions and the perceived severity of his or her crime are the major determinants of the penalty that is imposed.[28] Criminal history can account for a significant increase in penalty severity.[29] For example, a level fifteen[30] crime in the Federal Sentencing Guidelines mandates a presumptive penalty of eighteen to twenty-four months of incarceration for a first offender, and forty-one to fifty-one months for an offender with thirteen or more criminal history points.[31] A level thirty-five crime prescribes 168–210 months (or fourteen to seventeen and a half years) of incarceration for a first time offender, and 292–365 months (twenty-four to thirty and a half years) of imprisonment for an offender with the highest criminal history score.[32]

Although criminal history score and offense severity are the two most important considerations that influence the nature and severity of the criminal sanction, many other factors affect the decision about which penalty is imposed under the Federal Sentencing Guidelines as well.[33] Also, judges are allowed to deviate from a guideline[34] when certain mitigating and aggravating considerations apply; such considerations take the form of adjustments and departures.[35] Adjustments are considerations that increase or decrease the designated amount of a penalty.[36] For example, an offender who shows remorse can have his or her penalty decreased by up to two levels, while an offender who pleads guilty can have his or her penalty lowered by three levels.[37] Departures[38] also facilitate courts’ imposition of sentences outside a given guideline range.[39] 18 U.S.C. § 3553(b) empowers courts to use considerations that are not specified in the Guidelines as rationales for departing from the applicable guideline range.[40] However, when judges invoke 18 U.S.C. § 3553(b), they must specify their reason or reasons for stepping outside the range.[41] In other words, they must provide some details justifying their sentencing decision. Thus, even in a largely prescriptive guideline sentencing system, courts generally have a considerable degree of flexibility to adapt the penalty to the particular facts of the case and the profile of the offender.[42]

In United States v. Booker, the Supreme Court stipulated that the Federal Sentencing Guidelines were, in fact, advisory rather than mandatory,[43] and this is reflected in the practice that, each year, approximately 50% of the sentences imposed are outside of the penalty range set out in the Guidelines.[44]

Animal Cruelty Offenses and Their Sentences

No law at the United States federal level provides a general prohibition on animal cruelty. The recently enacted Preventing Animal Cruelty and Torture Act 2019 (PACT Act) has some relevance in this context, as it criminalizes the intentional infliction of “serious bodily injury” on an animal.[45] The PACT Act is not intended, however, to operate as general anti-cruelty statute, but instead is aimed at criminalizing acts of animal cruelty that underlie the creation of so-called “crush videos”, which themselves are criminalized by the Animal Crush Video Prohibition Act 2010.[46] Offenses under the PACT Act are subject to a fine, imprisonment of up to seven years, or both.[47]

There are nonetheless comprehensive animal cruelty statutes in all fifty states.[48] Sentencing law and practice for animal cruelty offenses generally fit within the approach to sentencing outlined above, but the nature and content of those crimes differs throughout the United States, and often, there are no prescribed minimum penalties.[49] We provide an overview of the law in this area and its application by examining examples of relevant legislation and cases in the five largest states in America.[50] This discussion contextualizes the reform proposals in the Article.

Overview of Legislation Concerning Animal Cruelty Offenses


California Penal Code § 597 is the primary law prohibiting animal abuse in California. Under this provision, “animal” refers to “every dumb creature” and thus, the provision covers a wide range of animals, including wild animals, strays, pets, and farm animals.[51] Under § 597, the following acts are prohibited:

  • Maliciously and intentionally torturing, maiming, wounding, mutilating, or killing an animal;[52]
  • Overloading or overworking an animal, or beating, hurting, or killing an animal, depriving an animal of food, water, or shelter from the weather, or abusing and/or causing an animal to suffer in any way;[53] or
  • Maliciously and intentionally maiming, mutilating, or torturing a reptile, bird, amphibian, mammal, or fish that is an endangered or protected species.[54]

A violation of any of these three offenses under Penal Code § 597 is punishable as a felony by imprisonment for a maximum of three years,[55] or by a fine of not more than $20,000, or by both that fine and imprisonment.[56] Alternately, a violation is punishable as a misdemeanor by imprisonment in a county jail for not more than one year, or by a fine of not more than $20,000, or by both that fine and imprisonment.[57]


The principal legal prohibitions on animal cruelty in Texas are found in the Texas Penal Code § 42.09, which prohibits cruelty to livestock, and § 42.092, which prohibits cruelty to non-livestock animals. For the purposes of § 42.09, livestock animals are defined as “cattle, sheep, swine, goats, ratites, or poultry commonly raised for human consumption;” “a horse, pony, mule, donkey, or hinny;” “native or non-native hoofstock raised under agriculture practices;” or “native or non-native fowl commonly raised under agricultural practices.”[58] This provision makes it an offense to treat a livestock animal, intentionally or knowingly, in any of the following ways:

  • Torture;
  • Unreasonably fail to provide necessary food or care;
  • Abandon;
  • Transport or confine in a cruel and unusual manner;
  • Administer poison without the owner’s consent (but note some animals are excluded from this provision);
  • Cause a livestock animal to fight with another animal;
  • Use a livestock animal as live bait for training dogs;
  • Trip a horse; or
  • Seriously overwork a livestock animal.[59]

Offenses under the above subsections (2), (3), (4), or (9) are Class A misdemeanors for the first offense,[60] for which the penalty is a fine not exceeding $4,000, imprisonment for no more than a year, or both.[61] Offenses under subsections (1), (5), (6), (7), or (8) are state jail felonies,[62] for which the penalty is imprisonment for a maximum of two years and minimum of 180 days, and a fine of up to $10,000.[63]

Under Texas Penal Code § 42.092, it is an offense to treat non-livestock animals, intentionally, knowingly, or recklessly, in a cruel manner.[64] For the purposes of this provision, an “animal” is defined as “a domesticated living creature, including any stray or feral cat or dog, and a wild living creature previously captured.”[65] Prohibited acts include the following:

  • Torturing an animal, or killing or causing serious bodily injury to an animal in a cruel manner;
  • Without the owner’s effective consent, killing, administering poison to, or causing serious bodily injury to an animal;
  • Failing unreasonably to provide necessary food, water, care, or shelter for an animal in the person’s custody;
  • Abandoning unreasonably an animal in the person’s custody;
  • Transporting or confining an animal in a cruel manner;
  • Without the owner’s effective consent, causing bodily injury to an animal;
  • Causing one animal to fight with another animal, if either animal is not a dog;
  • Using a live animal as a lure in dog race training or in dog coursing on a racetrack; or
  • Seriously overworking an animal.[66]

An offense under the above subsections (3), (4), (5), (6), or (9) is a Class A misdemeanor for the first offense,[67] which is a fine not exceeding $4,000, imprisonment for no more than a year, or both.[68] An offense under subsection (1) or (2) is a felony of the third degree for the first offense,[69] which may result in imprisonment for a maximum of 10 years and a minimum of two years, and a fine of up to $10,000.[70] An offense under subsection (7) or (8) is a state jail felony for the first offense,[71] which may result in imprisonment for a maximum of two years and minimum of 180 days, and a fine of up to $10,000.[72]

The scope of these provisions is limited, given that they do not apply to a range of other animals, including previously uncaptured wild animals, circus animals, and animals for experimental use.


In all of the laws in Florida that relate to animals, “animal” is defined as “every living dumb creature.”[73] The definition of “cruelty” in the same context includes “every act, omission, or neglect whereby unnecessary or unjustifiable pain or suffering is caused, except when done in the interest of medical science, permitted, or allowed to continue when there is reasonable remedy or relief.”[74]

Florida statute § 828.12 provides the primary legislative prohibition against animal cruelty in Florida. Pursuant to subsection (1), a person who “unnecessarily overloads, overdrives, torments, deprives of necessary sustenance or shelter, or unnecessarily mutilates, or kills any animal, or causes the same to be done, or carries in or upon any vehicle, or otherwise, any animal in a cruel or inhumane manner” commits the offense of animal cruelty.[75] This is a misdemeanor of the first degree,[76] and is punishable by a maximum prison sentence of one year,[77] a maximum fine of $5,000, or both.[78]

Under § 828.12(2) of the Florida statute, a person who “intentionally commits an act to any animal, or a person who owns or has the custody or control of any animal and fails to act, which results in the cruel death, or excessive or repeated infliction of unnecessary pain or suffering, or causes the same to be done” commits the crime of aggravated animal cruelty.[79] This is a felony of the third degree,[80] and is punishable by a maximum prison sentence of five years,[81] a fine of no more than $10,000, or both.[82]

New York

In New York, “animal” is defined in the Agriculture and Markets Law as “every living creature except a human being,”[83] and “torture” or “cruelty” includes “every act, omission, or neglect, whereby unjustifiable physical pain, suffering or death is caused or permitted.”[84]

Under Agriculture and Markets Law § 353, it is an offense to overload, torture, unjustifiably injure or kill, deprive of necessary sustenance, or in any way further an act of cruelty to any animal (wild or tame).[85] A violation under this section is a Class A misdemeanor, and attracts a maximum term of imprisonment of one year,[86] a fine of no more than $1,000,[87] or both.[88]

A person is guilty of aggravated cruelty to animals when “with no justifiable purpose, he or she intentionally kills or intentionally causes serious physical injury to a companion animal with aggravated cruelty.”[89] For the purposes of this section, “aggravated cruelty” is defined as “conduct which: (i) is intended to cause extreme physical pain; or (ii) is done or carried out in an especially depraved or sadistic manner.”[90] A violation of this provision is a Class E felony and carries a penalty of a term of imprisonment of no more than two years, and a fine of no more than $5,000.[91]


The Illinois Humane Care for Animals Act defines “animal” as “every living creature, domestic or wild, but does not include man.”[92] “Companion animal” is defined as “an animal that is commonly considered to be, or is considered by the owner to be, a pet . . . [it] includes, but is not limited to, canines, felines, and equines.”[93] It is a Class A misdemeanor under the Act to “beat, cruelly treat, torment, starve, overwork or otherwise abuse any animal,”[94] punishable by a maximum prison sentence of one year and a fine of no more than $2,500.[95] Causing a companion animal to suffer serious injury or death is a Class 4 felony punishable by up to three years of imprisonment and a maximum fine of $25,000.[96] The offender must have intentionally committed the act.[97]

Further, a person commits animal torture when he or she knowingly or intentionally tortures an animal.[98] For the purposes of this provision, “torture” means the “infliction of or subjection to extreme physical pain, motivated by an intent to increase or prolong the pain, suffering, or agony of the animal.”[99] This is a Class 3 felony and carries a five-year maximum prison sentence and a fine of up to $25,000.[100]

Summary of Current Animal Cruelty Criminal Offenses

As we have seen, animal cruelty is a criminal offense in each of the above jurisdictions. Yet, while four of the five largest states in the United States have adopted a broad definition of an animal in their legislation, Texas’s approach is notably narrow, as it excludes animals such as wild animals that have not previously been captured, circus animals, and animals used in experiments.[101] Moreover, the law in these five states does not define animal cruelty in a uniform way. Researchers have aptly observed, “conflicting state statutes and negligent enforcement of animal cruelty laws show a lack of national consensus on what constitutes animal cruelty.”[102] Indeed, the legal definitions of animal cruelty vary significantly between the jurisdictions.[103] Nevertheless, a commonality between these laws is that the animal cruelty offenses they create, focus on the infliction of physical pain on animals, though legislation in New York and Florida also criminalizes “neglect” that causes an animal “suffering,” as distinct from “physical pain,” which could encompass emotional distress.[104] The PACT Act reflects this shared focus on prohibiting the infliction of physical pain by expanding animal crushing to include “crushed, burned, drowned, suffocated, impaled, or otherwise subjected to serious bodily injury,” all of which relate to physical pain.[105]  Sentences available for animal cruelty offenses also vary between these states, and include prison terms ranging from one to ten years, and fines from $1,000 to $25,000.[106] Some states rely on human-use typologies when ascribing penalties.[107] For example, although all of the surveyed states included felony penalties for certain forms of animal cruelty, in New York, a felony penalty is only applicable where the animal that has been subjected to cruelty is a companion animal.[108]

Sentencing Practices Regarding Animal Cruelty Offenses

To contextualize the reform proposals in this Article further, we now briefly set out some examples of how animal cruelty laws have been applied in the five states mentioned above.


While the case law in California indicates a willingness on the part of California courts to impose relatively harsh sanctions on offenders who are convicted of animal cruelty, there appears to be some selectivity in the prosecutions that are brought to court. Many of the cases concern offenses that have been committed against animals that are companion or at least non-livestock animals. For example, in People v. Tom, the defendant, stabbed, beat, strangled, and then attempted to burn the dead body of a dog belonging to his girlfriend’s parents.[109] He was convicted under § 597(a) of the California Penal Code and sentenced to an aggregate term of five years and eight months in state prison.[110] Similarly, in People v. Burnett, the defendant intentionally threw a dog into oncoming lanes of traffic, resulting in the dog being killed.[111] He was found guilty of a violation of § 597(b) of the California Penal Code and sentenced to three years in state prison.[112] In another case, a woman kept ninety-two cats in a trailer and failed to provide adequate care for them, which led to the cats being dehydrated, malnourished, emaciated, covered in urine and feces, and suffering from a number of additional illnesses.[113] She was convicted of one count of animal cruelty under § 597(b) of the California Penal Code and was sentenced to five years of formal probation with a condition that she serve ninety-two days in county jail.[114]

While People v. Sanchez did relate to cruelty against farm animals, it did not concern animals housed in large-scale animal production premises.[115] In the circumstances of this case, a man left his residence for weeks at a time, leaving animals (including dogs, cows, rabbits, ducks, geese, and chickens) caged or tied up without access to sufficient food or water in extremely hot conditions.[116] He was convicted of seven counts of animal cruelty under § 597(b) of the California Penal Code and sentenced to state prison for a total term of four years.[117]

Some animal cruelty cases in California have related to animal fighting offenses. In People v. Baniqued, the defendants were involved in cockfighting, and tortured and killed roosters.[118] The defendants were convicted of several counts of animal cruelty under §§ 597(a) and 597(b) of the California Penal Code.[119] The Court imposed on each of the defendants four years of formal probation and payment of various fines.[120] More recently, the defendants in People v. Williams were each convicted of one felony count of dogfighting and one felony count of animal cruelty, and they were each sentenced to county jail for three years and eight months.[121] “The court suspended execution of [the] sentence[s] and placed both defendants on five years of formal probation on the condition that [the first defendant] serve 365 days in county jail, and [the second defendant] serve 270 days in county jail.”[122] Both “defendants were ordered to take anti-animal cruelty classes and were prohibited from owning or residing with any animals during the probationary period.”[123]


A review of the case law in Texas indicates that there is a strong focus in this state, too, on the prosecution of animal cruelty offenses that have been committed against companion animals or at least non-livestock animals. For example, in Justice v. State, the defendant was convicted of a single count of cruelty to a non-livestock animal for filming his co-defendant torturing and killing a newly weaned puppy.[124] The sentence of the defendant to fifty years of imprisonment took into account his two prior felony convictions for aggravated assault of a police officer.[125]

In 2015, in Amos v. State, the defendant was convicted of one count of cruelty to a non-livestock animal under § 42.092(b) of the Texas Penal Code after he beat a Shih Tzu dog to death with a broom.[126] The “offense constituted a state jail felony,” but “the State enhanced his offense with a prior murder conviction with an affirmative deadly weapon finding, making the offense punishable as a third-degree felony.”[127] The court sentenced him to thirty-one months of imprisonment (out of a possible 120 months)[128] in the Institutional Division of the Texas Department of Criminal Justice.[129] In another case in the same year, a man who shot a stray dog with a crossbow was convicted of the felony offense of animal cruelty under § 42.092(b)(1) of the Texas Penal Code and sentenced to the maximum term of imprisonment of two years.[130] More recently, a man pleaded guilty to one count of cruelty to a non-livestock animal after stabbing a dog with a knife, and he was sentenced to five years of imprisonment.[131]

In a different context, the owner of a non-profit cat sanctuary was convicted of four counts of non-livestock animal cruelty under § 42.092(b)(1) of the Texas Penal Code in 2011.[132] The sanctuary housed over 200 cats, and one employee was supposedly taking care of them.[133] When animal control officers entered the building of the sanctuary after receiving complaints, they found feces and urine all over the floor and walls, twenty-seven dead cats (some of whose bodies had been cannibalized by other cats), and cages with cats inside who had no food or water.[134] The cats that were still alive had various adverse health conditions, and were emaciated, terrified, and desperate for water.[135] The court placed the owner under community supervision for five years on each charge, to be served concurrently.[136]


Most of the cases determined in Florida that were reviewed also related to companion animals and, in particular, dogs. In Brown v. State, for instance, a woman was found guilty of felony cruelty to animals under § 828.12(2) of the Florida Statute after a dog was “found near [her] mobile home, emaciated and suffering” from several untreated long-term conditions.[137] The District Court of Florida held that the defendant owned the dog and had failed, “over a period of more than one year, to provide adequate food, water, and medical care” to it.[138] The defendant was sentenced to six months of community control, followed by three years of probation.[139]

More recently, however, the district court of appeals affirmed a conviction for felony cruelty to animals where the defendant shot an opossum “countless” times with a BB gun, and the animal needed to be euthanized as a result.[140] The court noted that the felony cruelty offenses under § 828.12 create a “potential tension” between criminal conduct and lawful hunting.[141] The commission of an act that causes a “cruel death” in § 828.12(2) applies even to the unintended consequence of a lawful act like hunting.[142] The court observed that this could be corrected “by amending the criminal statute to require that the actor intend to cause the results that the statute seeks to avoid—a cruel death or unnecessary pain or suffering.”[143]

New York

The cases reviewed from New York also reflect an apparent focus on prosecuting offenses relating to companion animals. For example, in People v. Garcia, a man stomped to death a pet goldfish, and was convicted of aggravated animal cruelty amongst other crimes (including assault, criminal possession of a weapon, and endangering the welfare of a child).[144] He was given an aggregate sentence of five and a half years to eleven years of imprisonment for all of the offenses.[145] In People v. Degiorgio, the defendant picked up a dog by the neck, shook him, and slammed his head against a door.[146] The defendant then threw the dog down the basement stairs onto a cement floor and kicked it.[147] He was sentenced to two years of imprisonment for aggravated cruelty to animals under § 353-a(1) of the Agriculture and Markets Law.[148]

The case of People v. Richardson was concerned with animal fighting. The defendant was convicted of three counts of felony animal fighting, one count of misdemeanor animal fighting, and two counts of cruelty to animals.[149] Police found, among other things, a wounded dog in a cage, numerous modified treadmills for use by dogs, blood on a water heater, and dogfighting paraphernalia at the defendant’s property.[150] In addition to the paraphernalia, the defendant’s dogs had extensive scarring and healing consistent with dogfighting.[151] The defendant was sentenced to a term of two years and eight months to eight years of imprisonment.[152]

An exception to this trend of prosecuting cruelty towards companion animals is the case of People v. Lohnes, where a man who broke into a barn and stabbed a horse to death was convicted of aggravated cruelty to animals under § 353-a(1) of the Agriculture and Markets Law.[153] The County Court sentenced the defendant to imprisonment, imposed a fine, and ordered payment of restitution.[154]

e. Illinois

Illinois case law relating to animal cruelty offenses also focuses on offenses against companion dogs. In 2008, a woman placed a towing chain around the neck of her pit bull dog, which caused a large, gaping hole to form in the dog’s neck and resulted in the dog being euthanized.[155] She was found guilty of aggravated cruelty to a companion animal under § 3.02 of the Humane Care for Animals Act and sentenced to thirty months of probation.[156] In People v. Robards, the defendant appealed her conviction for two counts of aggravated animal cruelty under § 3.02(a) of the Humane Care for Animals Act after her two dogs were discovered dead in her previous home.[157] The dogs were emaciated and dehydrated.[158] The defendant had moved out of that house and into another property.[159] Her landlord discovered a dog’s emaciated body on the living room floor, and police later discovered the other dog’s body in a garbage bag in the bedroom.[160] The defendant was sentenced to twelve months of probation.[161] On appeal, the defendant argued that the prosecutor failed to prove that she intended to cause serious injury or death to the dogs.[162] The appellate court rejected her argument and held that, for conviction, it is only necessary that the act itself was intentional, and it caused the death or serious injury of an animal.[163] The court further noted that the defendant was “very fortunate to have only received a sentence of twelve months of probation for these heinous crimes,” and criticized the lower court for its “unjustly and inexplicably lenient” sentence, simply because the defendant caused harm to an animal and not to a human being.[164]

Summary of Current Practice in Prosecuting and Convicting Cruelty to Animals

Thus, a review of the case law in the five largest states indicates that it is primarily offenses that are committed against companion animals and some non-livestock animals that are tried in court. Further, while some courts have shown a willingness to impose relatively heavy penalties on animal cruelty offenders, other offenders have received lenient sentences, which do not even include a short period of incarceration.[165] Notably, there is no consistency or uniformity regarding the penalties that have been imposed on animal cruelty offenders and the sentences for such offenses vary markedly.[166] Particularly illuminating for the purposes of this Article is the fact that there is no developed jurisprudence regarding or coherent approach to the sentencing of animal cruelty offenders.[167]

Objectives and Principles for Sentencing Animal Cruelty Offenders

As we have seen, there is a range of animal cruelty criminal offenses in all American jurisdictions. Yet, although relatively stern maximum penalties apply to those crimes, there is a lack of consistency in sentencing practice.[168] In order to evaluate the soundness of the current approach to sentencing animal cruelty offenders, it is necessary to examine the key objectives and principles that at present do, but also should, determine penalty severity. As we explain below, we argue that the principle of proportionality should be the major consideration for courts that are sentencing offenders for committing animal cruelty crimes.

Various sentencing objectives currently influence courts’ determination of the severity of the penalties that are imposed. The key sentencing aims are community protection, general deterrence and specific deterrence, and rehabilitation.[169] In a model sentencing system, however, only the objectives of community protection and rehabilitation should have, to a limited extent, an impact on the sanctions that they impose on animal cruelty offenders.

General Deterrence and Specific Deterrence

Although the objectives of general deterrence and specific deterrence operate to increase penalty severity, empirical evidence demonstrates that neither is efficacious in practice. There is a very small correlation between the imposition of harsher penalties and reduced commission of crimes.[170] The most effective means of lowering the crime rate is simply to make would-be offenders believe that, if they offend, they will be apprehended.[171] Consequently, the goal of general deterrence cannot be used to justify setting harsh penalties. A recent analysis of the incarceration rate of drug offenders and the distribution and use of illicit drugs illustrates the ineffectiveness of general deterrence.[172] A PEW Research Report in March 2018 noted that high levels of imprisonment for drug offenses do not reduce drug use or drug arrests.[173]

The objective of specific deterrence aims to discourage offending by individual offenders (rather than the community in general).[174] It is premised on the assumption that harsh penalties will teach offenders a lesson and discourage them from reoffending. Yet empirical data shows that this presumption, too, is flawed.[175] Harsh penalties in the form of prison terms, in fact, seem to have a slight criminogenic effect—they can increase the likelihood of reoffending.[176] Thus, the objectives of general deterrence and specific deterrence should not influence the sentencing of animal cruelty offenders.

Community Protection

The main manner in which the objective of community protection has been most vigorously pursued is by incapacitating offenders through imprisoning them. This confinement ensures that offenders cannot commit crimes in the community during the period of their sentences. The efficacy of imprisonment is, however, undermined in some situations by the fact that its financial cost can outweigh the benefit associated with preventing the commission of minor criminal acts, especially property, immigration, and low-level drug offenses.[177] Empirical data thus suggests that the sanction of imprisonment should be reserved for offenders who commit serious violent and sexual offenses.[178]

Ostensibly, the goal of community protection relates only to the protection of humans and hence would seem to be inapplicable to violence committed against animals. However, viewed more broadly, one could argue that some animal cruelty offenders do endanger the human community. Indeed, researchers Christopher Hensley, John Browne, and Caleb Trentham observe that “ignoring” human cruelty towards animals “may have devastating repercussions” not just for animals, but also for people.[179] There are several reasons for this. Cruelty towards animals lowers the moral tone of society. Abuse of pets can constitute a form of domestic violence if it causes family members distress, and the concern of victims of domestic violence for their pets’ welfare may prevent them from seeking refuge.[180] The American Psychiatric Association has listed animal cruelty as a symptom of conduct disorder, a condition involving behavior that violates others’ rights and social norms.[181] Especially significant is an apparent association between cruelty towards animals and commission of crimes against humans: individuals who are cruel to animals may either concurrently or subsequently engage in behavior that harms people.[182]

For many years, philosophers, academics, and animal welfare rights groups conjectured that there was a link between cruelty towards animals and interpersonal violence in particular.[183] Researchers have now tested and found empirical evidence to substantiate two theories regarding this connection: (i) the “graduation” or “progression” thesis; and (ii) the “deviance generalization hypothesis.”[184] We now explain and discuss the evidentiary support for each of these theories in turn.

According to the progression thesis, an individual’s cruelty towards animals in childhood can precipitate their commission of offenses against humans in later life.[185] Therefore, individuals who are cruel to animals are subsequently more likely to behave aggressively towards other people, and those who behave aggressively towards other people are more likely than those who do not to have been cruel to animals previously.[186] It had been observed for some time that many serial killers had behaved cruelly to animals in their early lives.[187] Initial studies of the progression thesis nonetheless yielded varied results, though the inconsistencies were seemingly attributable to differences between and limitations of the methodologies used.[188] More recent studies, using varied means of data collection (including self-report surveys, interviews, and case studies) and examining recurrent offenses, have confirmed a strong link between several acts of cruelty towards animals in childhood and subsequent aggressive behavior in adulthood.[189] Consequently, it is clear that those who have behaved cruelly towards animals during childhood are at greater risk of committing violent offenses against people in later life.[190]

Some significant studies illustrate this connection. In 2001, Linda Merz-Perez, Kathleen Heide, and Ira Silverman published the results of their study of forty-five violent and forty-five nonviolent Florida prisoners, which drew on a wide range of data about them.[191] They found that offenders who committed violent crimes as adults were substantially more likely than those who committed nonviolent offenses to have committed acts of cruelty against animals as children (56% compared with 20%).[192] The former group also tended to commit acts of cruelty towards animals that involved physical contact with them, and less of the violent offenders than the nonviolent offenders expressed remorse for this behavior.[193] A publication in 2012 by Christopher Hensley, Suzanne Tallichet, and Erik Dutkiewicz following a study of 180 male prison inmates in a southern state, which focused on different forms of animal cruelty committed during childhood, revealed that 103 of the participants reported having engaged in animal cruelty.[194] Those who admitted to committing multiple acts of animal cruelty during childhood were more likely to have committed violent acts against humans as adults, and those who had engaged in bestiality (sex with animals) during childhood were particularly likely to have committed violent crimes in adulthood.[195]

In 2019, C. Longobardi and L. Badenes-Ribera published a systematic review of thirty-two studies that had been undertaken between 1995 and 2017, and investigated the relationship between animal cruelty committed during childhood and adolescence, and later interpersonal violence.[196] Retrospective studies of prisoners confirmed that “acts of animal cruelty committed during childhood and adolescence are a relatively persistent predictor of adult interpersonal violence,” and prospective studies similarly found that “animal cruelty precedes [violent and nonviolent] offenses.”[197] Prisoners who committed recurrent acts of childhood animal cruelty, and especially drowning animals or engaging in sexual acts with them, were more likely to have engaged in repeated acts of interpersonal violence as adults, even after controlling for demographic and other factors.[198]

According to the deviance generalization hypothesis, individuals who are cruel to animals are likely also to engage in other violent and nonviolent criminal behavior.[199] Reasons postulated for this are that involvement in one form of deviant behavior leads to involvement in others, and these behaviors are motivated by the same factors.[200] Longobardi’s research also found empirical support for this theory and particularly that more serious offenses are often committed in addition to animal cruelty, including among non-prisoners, especially where recurrent acts of animal cruelty are committed.[201]

Considerable research has demonstrated that abuse of pets in particular often coexists in families that are afflicted by domestic violence.[202] Several studies found that a high proportion of women who sought refuge from domestic violence in various programs and refuges reported that their pets had also been abused in their homes.[203] Indeed, research conducted in the United States, including by Frank Ascione and others, found that women in domestic violence shelters were nearly eleven times more likely to report that their partner had hurt or killed their pets than a comparison group of women who had not experienced intimate violence.[204] The results of an Australian study reported in 2008 are consistent with this co-occurrence of animal abuse and interpersonal violence amongst adults:[205] the reported rate of partner pet abuse among women who had experienced domestic violence was 52.9%, compared to 0% among a group of women who had not experienced domestic violence reported pet abuse.[206]

In light of the link between animal cruelty offenses and offenses that inflict harm on people, the objective of community protection should, to some extent inform the sentencing of animal cruelty offenders.


The sentencing objective of rehabilitation is generally invoked to mitigate penalty where an offender demonstrates that he or she is reformed since committing the relevant crime,[207] and has no or few prior convictions. Providing that such evidence is produced, it would be reasonable for this goal to have an impact on the penalty that is imposed for animal cruelty offenses.


As noted above, we consider that the key principle that should influence the sentencing of animal cruelty offenders is proportionality. In its broadest expression, proportionality is a doctrine that stipulates that there must be compatibility between an act or objective and the means employed to achieve it.[208] It acts as a restraint on the measures that can be taken to achieve desired outcomes. The proportionality principle strikes a strong intuitive chord and, probably, for this reason, is applied in many areas of the law. As Richard G. Fox notes, the notion that the “response must be commensurate to the harm caused, or sought to be prevented,” is at the core of the criminal defenses of self-defense and provocation.[209] It is also the foundation of civil law damages for injury or death, which aims to compensate for the actual loss suffered, and equitable remedies in common law countries, which are “proportional to the detriment sought to be avoided.”[210]

The justification for the proportionality principle is that benefits and burdens should be distributed with regard to, and be commensurate with, a person’s merit or blame.[211] Such a division of benefits and burdens ensures that our society is just and fair. If benefits and burdens were randomly distributed, we would have little motivation to strive hard to succeed or to avoid engaging in harmful conduct. The principle of proportionality is particularly applicable in the area of sentencing, where it entails that the severity of the punishment, and thus the hardship imposed on the offender, must match the seriousness of the crime.[212]

Proportionality in sentencing is widely endorsed and embraced. It is a requirement of the sentencing regimes of ten states in the United States.[213] Proportionality is also a core principle that informs (though it does not strongly influence) the Federal Sentencing Guidelines.[214] In addition, as a survey of state sentencing law by Thomas Sullivan and Richard Frase demonstrates, at least nine states have constitutional provisions relating to the prohibition of excessive penalties or treatment (which reflect an endorsement of proportionality),[215] and twenty‐two states have constitutional clauses that prohibit cruel and unusual penalties, including eight states with a proportionate‐penalty clause.[216]

The contours of the proportionality principle are unclear. Scholars have observed that there is no stable and clear manner in which the hardship of the punishment can be matched to the severity of the crime.[217] However, it is widely accepted that the most important indicator of the seriousness of an offense is the suffering or pain that it has caused.[218] Behavior that does not cause any physical suffering may nonetheless still indicate the gravity of the offense if it infringes social norms or induces psychological or emotional suffering, for instance, by causing an individual shame, embarrassment, or indignation.[219] Examples of this type of conduct, which is punishable by criminal sanctions, include spitting in public and distributing photographs of nude people.

In applying the principle of proportionality in sentencing for animal cruelty crimes, it will be important for courts to consider whether such offending is more serious and thus warrants the imposition of a harsher sanction if it results in the animal’s death. The most serious offense that humans can commit against one another is homicide, so application of the principle of proportionality in sentencing an offender for this crime would result in a relatively severe sanction being imposed. Yet, given that humans slaughter such a high volume of animals for food and many animals, such as ants and flies, have minimal cognitive capacity, it would be contrary to current social norms for a sanction to be imposed simply for killing an animal. Indeed, the notion that animals’ lives are as sacred as those of humans does not align with popular contemporary normative values. One of the major arguments that has been raised in debates regarding euthanasia and abortion of humans is that they do not take into account the sanctity of life.[220] It is unlikely, at least in the near future, that such a position would be taken in relation to animals, especially because they constitute a staple of many people’s diets.

Nevertheless, where human cruelty towards an animal results in its death, we consider that this fact could aggravate the offense if the animal is conscious of its ongoing existence; has a preference for living; the animal’s death also causes suffering to a human; the animal’s death causes suffering to another animal who depended on the animal that was killed; or all of the above. This is consistent with the two major rationales for imposing a harsher sanction if an act of violence against a person causes his or her death. First, human beings as a species generally exhibit an understanding of their ongoing existence and the concept of the future.[221] Thus, in considering the seriousness of a violent act that is committed against a human, conduct that eliminates that expectation of a future has the impact of aggravating the offense. While some humans, such as infants and the severely mentally disabled, may not be capable of such understanding, it would be socially unacceptable to discriminate against them in sentencing violent offenders for crimes committed against them. Second, violent crime that results in human death can also cause suffering to other humans (and animals), including those that depend on them.

Many animal species do display an awareness of their own existence and expectation of their future existence.[222] Charles Darwin famously observed in his Descent of Man, “the difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind.”[223] Ed Wasserman, a researcher from the University of Iowa, would agree. He has commented:

The notion that there might only be a quantitative—not a qualitative—disparity between human and animal intelligence may make people uneasy . . . [however] [t]he evidence that we collect constantly surprises us, suggesting that we’re not alone in many of these cognitive abilities. [So] [w]hy we would believe that humans alone have such capabilities is a peculiar and unfortunate arrogance. That’s one reason why I enjoy studying animals; the smarter we discover them to be, the more humble we should be.[224]

Although scientists do not fully understand animals’ cognitive capacities, they have observed that certain animals have a degree of self-awareness, are conscious of their ongoing existence, and therefore have a preference for living over dying.[225] This is evident from studies that have shown that monkeys (Mucaca mulatta), chimpanzees, orangutans, gorillas, elephants, and dolphins recognize themselves from their reflections in mirrors.[226] In these studies, researchers painted these marks on the animals while they were unconscious and, when they woke up, they were given mirrors, which the animals used to examine themselves and locate the marks.[227] These animals’ capacity for self-recognition indicates that they are aware that they are independent beings and, by extension, that other beings have their own identities, too.[228]

Experiments conducted by comparative psychologist, Dr. David Smith,[229] demonstrated that some animals are even capable of metacognition, which is the capacity to think about thinking and have an awareness of one’s own mental states.[230] In particular, dolphins and macaque monkeys showed that they were capable of experiencing uncertainty and reacting accordingly (whereas pigeons did not display this capacity).[231] In other experiments with apes and chimpanzees, these animals engaged in behavior that appears to demonstrate that they expect the order of future events and are aware of themselves being “distinct entities” existing over time.[232] Thus, for animals that are conscious of their existence and that exhibit an expectation of their future existence, a harsher sanction should apply to crimes against them that result in their death than would otherwise be imposed for such offenses.

As noted above, in relation to other animals who do not exhibit this consciousness of their own existence and preference for remaining alive, we maintain that the death of such animals as a consequence of human cruelty would only aggravate the severity of the offense where their death causes suffering to humans or to other animals that depend on them. This is because, to the extent that there is no evidence that the animal has such awareness, one of the primary rationales for considering death to be an aggravating factor no longer applies. Nevertheless, if the animal is the pet of a human, their death could cause the owner significant distress. Many pet owners regard their pets as members of their families and even “surrogate relatives,” and depend on them for companionship and enjoyment.[233] Research has shown that people’s relationships with their pets can be “critical in determining [their] mental equilibrium” and pets can “play a positive psychosocial role in the home,” especially for people who live alone.[234] There is substantial evidence that, as a consequence, the death of a pet can be an extremely traumatic event for their human owner and mirror a person’s experience of the death of a human partner or other relative.[235] Gerald Gosse and Michael Barnes published the results of their study that measured the bereavement levels of 207 adults from New York, whose pet dogs or cats had died in the year before participating in this research.[236] They found that “high attachment [to the pet], low social support and an accumulation of other stressful events would be associated with high levels of grief,” and certain “bereaved pet owners” may in fact “be predisposed toward social isolation.”[237] Kenneth Keddie also documented the “disabling psychiatric symptoms” and “pathological grief” that three women suffered following the deaths of their pet dogs.[238]

The death of an animal owing to human cruelty might also increase the gravity of the offense and warrant the imposition of a harsher sanction if it causes physical or psychological pain to or the death of another animal that depended on the deceased animal. This would occur most typically when the killed animal has offspring who suffer, for example, by starving, because of their parent’s death.

For the purpose of applying the proportionality principle, three matters, in particular, indicate that human cruelty towards animals is extremely serious and warrants the imposition of harsh sanctions. First, as we shall see below, scientific investigation has established that certain animals feel physical pain and that there is no relevant distinction between the physical pain sensations experienced by animals and humans.[239] Scientific research has confirmed that animals can also experience psychological harm.[240] Second, according to current social norms, it is inappropriate for humans to cause animals to unduly suffer pain.[241] Third (and in part due to scientific evidence that cruelty towards some animals can cause them to experience pain),[242] pursuant to the two major streams of moral philosophy, certain animals have moral standing. Consequently, it is unethical to cause them to suffer unnecessarily, and it is essential for the law to protect them.

We now examine in greater detail these considerations, which we argue should inform both the classification of animal cruelty offenses and sentencing of them.

Matters That Should Inform Classification and Sentencing of Animal Cruelty Offenses

As noted above, in this part of the Article, we consider scientific, normative, and philosophical bases for penalizing cruelty towards animals and, especially in respect of scientific evidence, determining the gravity of this offending. We begin by reviewing the scientific research concerning animals’ capacity to feel pain. We then consider social norms regarding human interaction with animals. Finally, we examine moral theories that establish that, in light of scientific evidence and social norms, animals have moral standing.

Scientific Research Regarding Animals’ Capacity to Feel Pain

A compelling reason for punishing offenders who behave cruelly towards others is the desire to eliminate or reduce pain. Yet it has been difficult for scientists to prove conclusively that animals in fact experience pain because there is no universal, incontrovertible, objective measure for detecting and evaluating pain, even in humans; pain is a subjective experience for any living creature; and animals do not necessarily express pain in similar ways to humans.[243] Recent scientific evidence does nonetheless confirm that many animals do feel physical pain and that it resembles the pain that humans experience.[244] There is also scientific evidence that at least some animals experience psychological suffering.[245] We argue that this research indicates the impact on animals of cruelty offenses and thus should affect the law regarding them, including how the principle of proportionality is applied to assess the gravity of the offending and determine fitting sanctions for these crimes.

We now discuss this research, first regarding animals’ experience of physical pain and then concerning their psychological suffering.

Animals’ Experience of Physical Pain

As animals do not communicate and convey any pain that they might experience in the same manner as humans, it is difficult for people to recognize whether animals, in fact, suffer from pain. Nevertheless, scientists have developed three approaches to evaluate whether animals experience pain, all of which rely on their observations of animals. These methods are anthropomorphic,[246] as they examine whether animals experience similar physiological and behavioral reactions to pain as humans. The first method involves measuring animals’ bodily functions (such as their consumption of food and water); the second entails evaluating their physiological responses (specifically by examining the concentrations of plasma cortisol in their bodies); and the third encompasses assessment of animals’ behavior (which might include matters such as their vocalization and physical movements).[247] Scientists have gleaned, particularly from application of the third measure, that many animals do feel physical pain.[248]

Specifically, scientists have interpreted from the fact that many species of animals and especially mammals, primates, and vertebrates (though some invertebrates, too) exhibit similar behavioral reactions to pain stimuli as humans—such as screaming or thrashing about in response to a physical attack—that they share humans’ physical system for recording pain, which is described as “nociception.”[249] Scientists believe that certain animals, like humans, have nociceptors, which are nerve ends, in various parts of their bodies.[250] Nociceptors receive a message of potential pain or noxious stimuli, and transmit this message through the spinal cord to the brain, whose sensory cortex processes it and in turn forwards the message to other parts of the body that exhibit pain symptoms, for instance, through vocalization or movement.[251] Animals whom scientists have found display these responses to physical pain are vertebrates, such as guinea pigs,[252] rats,[253] horses,[254] and farm animals, including chickens, cows, and sheep.[255] Perhaps surprisingly, scientists have found that even some invertebrates, including leeches, crustaceans, and sea slugs, also have nociceptors, while fish have sensory neurons that can similarly detect sources of pain.[256] Observation of these animals indicates that they experience pain, too.[257]

Scientist, Lynne Sneddon, cautions that it is hard for scientists to ascertain the nature of animals’ pain because it is a subjective experience.[258] She notes that:

Whether animals can feel pain has been a controversial issue for many years. Animals and humans share similar mechanisms of pain detection, have similar areas of the brain involved in processing pain and show similar pain behaviours, but it is notoriously difficult to assess how animals actually experience pain.[259]

Nevertheless, the weight of evidence confirms and the international scientific community has accepted that many animals can feel physical pain and that they experience it in a similar manner to humans.[260] Various bodies around the world (including Australia’s National Health and Medical Research Council, the Association for Assessment and Accreditation of Laboratory Animal Care International, and the Department of Agriculture in the United States, and the United Kingdom Animal Procedures Committee) have prescribed guidelines for research that involves animals, which in fact require the use of methods for reducing animals’ pain in these studies.[261] In addition, veterinarians and others who work with animals administer analgesics and anesthetics to animals in order to minimize their pain, and where they consider that they are observing animals suffering from unbearable pain, they euthanize them.[262] Scientists have also developed tables for measuring animals’ pain levels.[263]

Animals’ Experience of Psychological Harm

There is now a general consensus among scientists that animals can also experience psychological harm. Though some regard this conclusion as a “common-sense” one,[264] reaching it has proven difficult. The methods that scientists have developed for measuring animals’ physical pain are not necessarily useful in ascertaining whether they experience psychological harm. To experience this form of pain, a living being must feel particular emotions. Yet emotions are experienced internally and often lack any external manifestation or expression. Moreover, if animals do experience emotions, they may exhibit them in a very different manner from humans or at least in ways that humans do not recognize. Nevertheless, scientists have observed that some animals, and especially those with advanced cognition, indicate that they feel emotions.[265] Further, scientific investigation has confirmed that “[a]natomical, physiological, and behavioral similarities across species demonstrate that animals experience pain and distress [including psychological pain and distress] in ways similar or identical to humans.”[266] Moreover, not only do animals experience psychological harm in a similar way to humans, but the same factors contribute to the experience of mental suffering in both humans and other animals.[267]

There have been many anecdotal observations of animals’ apparent emotional responses to both upsetting and uplifting events. For instance, in the Münster Zoo in northern Germany, a gorilla, Gana, appeared to be devastated and grief-stricken as she embraced and stroked her three-month-old baby who had died, and she gently shook the baby seemingly in an attempt to revive it.[268] At the other end of the emotional scale, scientist Klaus Wilhelm notes that, “[i]n the rain forests of Sumatra, orangutans swing from branches and splash their hands into pools of water with no other apparent purpose than just for the fun of it.”[269] For many years, scientists have hypothesized that animals such as pigs experience depression when they are confined in small spaces and denied the opportunity to pursue behavior that is usually undertaken by their species.[270] Some scientific studies support these observations that animals with greater cognition, in particular, can respond emotionally to their experiences.[271]

Scientists distinguish between animals’ capacity to feel primary emotions on the one hand, such as fear and surprise, and social emotions on the other, which demand some level of self-reflection and whose expression contributes to the dynamics of the community in which animals live.[272] Many animals appear to have primary emotions and especially fear. Animals with greater cognitive ability also seem to display social emotions,[273] including sympathy, brashness, humiliation, shame, guilt, and avarice. Biologists have observed that some animals experience joy, too, which Wilhelm conjectures is reflective of the operation of complex brain processes and self-awareness, and also contributes to animals’ negotiation of their relationships:

Feelings . . . well up from the analytical mind. Someone who “feels good,” who experiences joy, is aware of her body being in a particular state. The perception of such a feeling requires processing by several somatosensory brain regions in the cerebral cortex that map parts of the body and their condition and, simultaneously, brain activity that assesses what those conditions mean. In essence, this processing constitutes self-reflection . . . It is well accepted that young mammals have an inborn drive to play, because the interaction helps them sort out social opportunities and limits. They learn skills that will be important to their later survival.[274]

Significantly, according to analyses of animal and human brains’ metabolism, animals and humans share “similar physical brain processes,” including “the neurotransmitter dopamine,” which, at least in humans, leads to them experiencing and expressing the emotion of joy.[275]

It has also been found that animals are capable of experiencing psychological illness.[276] According to Franklin McMillan, “[a] rapidly proliferating literature provides extensive evidence supporting the existence of psychological trauma and its characterization in nonhuman species.”[277] For example, research in relation to chimpanzees has shown that they can behave in ways that suggest the existence of generalized anxiety disorders, obsessive-compulsive disorders, and post-traumatic stress disorder.[278] A number of studies have been published regarding the experience of post-traumatic stress disorder also in other animals, including wolves, elephants, and dogs.[279]

Similar factors have been shown to contribute to the experience of psychological suffering in both humans and animals.[280] In studies undertaken in relation to chimpanzees, potentially traumatic experiences endured by them when they were the subjects of experimental research, such as confinement, physical harm, and isolation, led to the chimpanzees developing behaviors associated with post-traumatic stress disorder, depression, anxiety, and obsessive-compulsive disorder.[281] Similarly, studies in relation to dogs that were sold as puppies through pet stores, born in commercial breeding establishments, or both indicated an increase in behavioral and emotional problems that cause distress, including aggression and fear, when compared with dogs from other sources.[282] Factors that contributed to these problems likely included stress, stimulus deprivation, and maternal separation.[283] Further, abuse, neglect, confinement, multiple re-homing, natural disasters, fighting, racing, forced work, experiences in armed conflict, experiences as laboratory subjects, and physical trauma and injury are cited as potential causes of psychological trauma in animals.[284]

As we have seen, scientists accept that animals are capable of experiencing physical pain. In addition, it is clear that animals can feel emotions and experience psychological harm. This scientific research thus provides a justification for criminalizing conduct that causes animals to suffer physical and/or psychological pain. Moreover, if scientists can measure the degree of pain that animals experience as a consequence of human cruelty, this evidence can inform the application of the principle of proportionality in determining an appropriate penalty.

Social Norms Regarding Humans’ Interaction With Animals

A strong connection exists between criminal law and normative values,[285] as contemporary norms determine the behavior that is criminalized and the sentences that are imposed. Moreover, the law will only be respected, upheld, and enforced if it reflects, at least to some extent, contemporary normative values. For this reason, we argue that some current normative values should influence definitions of animal cruelty and the law’s responses to animal cruelty offenses. Nevertheless, we do not recommend integrating all of society’s current norms regarding humans’ relationships with animals into laws relating to animal cruelty offenses. We take this position for a number of reasons. First, social norms relating to the relationships between humans and animals are in a state of rapid change, as evidenced by the swift rise of the vegan movement. Second, some social norms in this context appear to conflict with one another. For example, normative values indicate that animals should not suffer unnecessarily, and yet it is socially acceptable and commonplace to kill fish by tugging them out of the water with a hook in their mouths and leaving them to suffocate, and to place lobsters while they are still alive in boiling water to cook them. Finally, while it is important that the law reflects social norms, it is also the case that the law has an important role to play in helping to shape normative values. Notwithstanding these views, we now examine some current normative values that we consider the law does need to reflect.

We believe that it is important that law-makers acknowledge that humans eat animals, and it is not foreseeable, at least in the near future, that killing animals for human consumption will be criminalized. The law should take into account other ways in which humans depend on animals, too, including for sport, entertainment, companionship, and medical testing, which are similarly unlikely to be abandoned imminently. Yet it is also accepted that, in light of humans’ reliance on animals, they bear responsibility for treating them well, especially because it is recognized that they are less powerful than people and thus vulnerable to their exploitation. Indeed, the overarching normative value regarding the relationship between humans and animals that, in our view should inform the law, is that humans should not cause animals to suffer unnecessarily. Even where people kill animals for human consumption or other purposes, it is commonly expected that this will be performed as swiftly as possible to eliminate any gratuitous suffering that might accompany it. The adoption of animal welfare legislation in numerous jurisdictions indicates the importance of this value in contemporary society. Moreover, the growth of scientific evidence that some animals are sentient and can experience physical and psychological pain will bolster (if it has not already) social norms that humans should not inflict pain on animals unduly.

Society still deems humans as warranting greater protection than animals, and, as discussed above, an animal’s life is not accorded the same sanctity as that of a person. It is, therefore, imperative to compare penalties for offenses against humans and animals because society would likely not accept the imposition of harsher sanctions for the latter than the former.

Animals’ Moral Standing

As social norms are informed by morality, it is important to consider popular moral theories in determining how the law should address human cruelty towards animals. In particular, this philosophy can indicate if we should take into account animals’ interests in deciding whether human behavior towards them is morally upright or not, and whether it is ethically imperative for the law to protect them from human cruelty. In this regard, it is especially important to ascertain whether, pursuant to the major streams of moral theory, animals can be regarded as having moral standing. If animals lack moral status, there is no justification for granting them any greater legal protection than an inanimate object. Yet we argue that, according to the two major schools of moral philosophy, animals should be accorded moral standing and, at least in relation to one of those streams, on the basis of scientific evidence that many animals experience pain. As discussed above, although animals’ lives are generally not regarded as being sacred, many would consider the lives of animals with more advanced sentience and cognition, in particular, to be intrinsically important. The notion that animals have moral standing is consistent with this normative understanding. Animals’ moral status provides a further, and in this instance, ethical, reason for criminalizing animal cruelty offenses and for treating those crimes as being especially grave. We now explain these points in greater detail.

Overview of Moral Theories

In addition to the fact that animals can experience pain, another basis for arguing that it is inappropriate to inflict cruelty on them is that they have moral status or standing,[286] which means that animals can be recognized as legitimate members of the moral community who deserve protection.[287] Prior to explaining why we maintain that animals have moral status, we provide a brief overview of the main moral theories that justify the ascription of moral standing.

Most moral theories fall into two broad groups, namely, consequentialist and non-consequentialist theories.[288] According to consequentialist moral theories, an act is right or wrong depending on its capacity to achieve a particular outcome, such as to maximize a virtue, for instance, happiness.[289] By contrast, according to non-consequentialist (or deontological) theories, the appropriateness of an action is not contingent upon its ability to produce particular ends, but rather follows from the intrinsic features of the act.[290]

Consequentialist Theories

The most popular consequentialist moral theory is utilitarianism.[291] Several different forms of utilitarianism have been proposed, the most influential of which is hedonistic act utilitarianism.[292] This theory provides that the morally right action is the one that produces the greatest amount of happiness or pleasure and the least amount of pain or unhappiness.[293] According to this theory, all individuals’ interests count equally to one another, and we should act in a manner that maximizes net human well-being.[294]

Utilitarianism has fallen out of favor in the Western world over the past fifty to sixty years for several reasons. The main general argument against utilitarianism is that, because it prioritizes net happiness, it fails to safeguard fundamental individual interests. As a result of this, it has been claimed that, in some circumstances, application of a utilitarian theory would lead to undesirable outcomes, such as punishing the innocent.[295] For instance, a few individuals might suffer some extreme sanction in order to quell large-scale civil disobedience, or some people may be compelled to have their organs removed because transplantation of them would maximize happiness by saving the lives of others and assisting those most in need of them.[296]

Another significant criticism of utilitarianism is that it is incompatible with the concept of rights.[297] Utilitarianism is a maximizing principle, as it aims to maximize net happiness. By contrast, the notion of rights is individualizing, as its purpose is to accord each individual certain interests and uphold them.[298] Some critics of utilitarianism maintain that, in prioritizing net happiness over individual sacrifices, it does not take seriously the distinction between human beings and fails to protect certain rights and interests, which should be regarded as paramount.[299] Another major stream of moral theory, which we discuss next, does prioritize individual rights.

Non-consequentialist (Deontological) Theories

According to non-consequentialist or deontological theories, the appropriateness of an action depends not on its ability to produce particular ends, but rather on its intrinsic features.[300] On the basis of such theories, consequences are either an irrelevant or subsidiary consideration in evaluating the morality of an act.[301] The types of norms that are prioritized above consequential considerations in these theories are often derived from sources such as religion or the supposed state of nature.[302]

Deontologists place greater importance on complying with these norms than on producing desirable outcomes.[303] For instance, if a deontological theory asserted that lying was morally wrong, according to this theory, one should not lie to a would-be murderer about the true location of his intended victim because the commission of an immoral act cannot be justified even by the fact that it will result in positive consequences. By contrast, in this situation, a utilitarian would lie to the would-be aggressor about the victim’s location in order to prevent the victim’s death and thus maximize net human flourishing.

The most popular deontological theories are based on rights and, in particular, human rights.[304] These theories gained adherents, especially following World War II due to a determination to prevent a repetition of atrocities that occurred during that war in the future.[305] Those who subscribed to deontological theories maintained that it would be less likely that such egregious abuses might be committed again if individuals’ innate rights were recognized.[306] Since then, there has been an increased tendency to base moral arguments on and express moral sentiments in terms of rights.[307] As L. W. Sumner notes, “there is virtually no area of public controversy in which rights are not to be found on at least one side of the question—and generally on both.”[308] Indeed, the notion of human rights has, at this point in time, supplanted the objective of maximizing utility as the leading philosophical inspiration for those who are advocating for political and social reform.[309] Certainly, rights claims have historically proven to be highly effective in bringing about social change. As Tom Campbell observes, they have provided “a constant source of inspiration for the protection of individual liberty.”[310] “For example, recognition of the (universal) right to liberty resulted in the abolition of slavery.”[311] More recently, women and other disenfranchised social groups have succeeded, at least to some extent, in improving their status by arguing for the right of equality.[312]

Application of Consequentialist and Non-consequentialist Theories to Justify Animals’ Moral Status

Notwithstanding the increasing popularity of non-consequentialist and, especially, rights theories, there is an ongoing philosophical debate about whether they are more sound than consequentialist theories. Despite the superficial appeal of rights theories, some argue that they lack an epistemological basis and, accordingly, it is impossible to distinguish between real and fanciful rights, and to ascertain the respective priorities of rights that clash with one another.[313] Nevertheless, for the purpose of this Article, it is unnecessary to reach a determination about which of these streams of moral theory should predominate. Importantly, application of both of them leads to the conclusion that animals have moral status, though a more compelling argument for protecting animals’ interests may be grounded in consequentialist theories in light of scientific evidence of animals’ capacity to feel pain.

Some philosophers who subscribe to consequentialist theories have already recognized that animals have moral status. Writers such as Scott Wilson, in fact, justify their position on the basis that animals have “sentience,”[314] which is defined as “the capacity for sensation or feeling;”[315] a “sentient” being has “sensation or feeling” or “the power or function of sensation or of perception by the senses,” is “responsive to sensory stimuli,” or “feels or is capable of feeling.”[316] Peter Singer, whose book, Animal Liberation, which was published in 1975, was one of the catalysts for the emergence of the animal liberation movement, and other utilitarians, including pathocentric bio-ethicists, focus especially on animals’ ability to feel pain, and possibly also to suffer.[317] As we have discussed, scientific research has now established that many vertebrates, in particular, have the capacity to feel pain, though pain may be distinguished semantically from suffering.

The reason why animals’ capacity to feel pain, in particular justifies ascribing to them moral status according to consequentialist theories is evident from the writings of one of the fathers of utilitarianism, Jeremy Bentham. Bentham stated:

The day may come, when the rest of the animal creation may acquire those rights which never could have been withholden from them but by the hand of tyranny. The French have already discovered that the blackness of the skin is no reason why a human being should be abandoned without redress to the caprice of a tormentor. It may one day come to be recognized, that the number of legs, the villosity of the skin, or the termination of the os sacrum are reasons equally insufficient for abandoning a sensitive being to the same fate. What else is it that that should trace the insuperable line? Is it the faculty of reason, or, perhaps, the faculty of discourse? But a full-grown horse or dog is beyond comparison a more rational, as well as more conversable animal, than an infant of a day, or a week, or even a month, old. But suppose the case were otherwise, what would it avail? the question is not, Can they reason? nor, Can they talk? but, Can they suffer?[318]

As utilitarians argue that the only considerations that are relevant to assessing the morality of an act are whether it results in happiness or pain, certain animals’ capacity to feel pain means that, according to this moral theory, they have interests and that those interests must be taken into account in determining the morality of behavior towards them.[319]

Although non-consequentialist theories, and particularly rights-based moral theories, were initially developed to address human interests,[320] they are equally applicable to animals and can similarly be deployed to justify the position that animals have moral status and thus deserve legal protection. This is evident from an analysis of philosophers’ interpretations of the nature and meaning of rights.

Wesley Hohfeld identified four categories of rights, namely, claim-rights, privileges, powers, and immunities, though he considered that only claim-rights fell strictly within the meaning of this term.[321] Since then, many definitions of rights have been propounded, some of which explicitly refer to humans. For instance, John Kleinig explains that rights are “those minimum conditions under which human beings can (that moral agents) flourish and which ought to be secured for them, if necessary by force.”[322] Likewise, Thomas Hobbes maintained that rights reflected “the liberty each man hath, to use his own power, as he will himself, for the preservation of his own nature.”[323] Yet it is arguable that references to humans in these definitions merely illustrate the nature of rights, and there is no reason why they could not be applied to animals.

There is also no theoretical impediment to applying to animals other, broader definitions of rights, which focus on what rights endow to the holders of them, particularly in the form of claims or entitlements.[324] For instance, H. McCloskey maintains that rights are effectively entitlements,[325] and Tom Campbell clarifies that “[t]he standard view is that rights are moral entitlements.”[326] Alternately, T. Sprigge considers simply that “[t]he best way of understanding . . . that someone has a right to something seems to be to take it as the claim that there are grounds for complaint on their behalf if they do not have it.”[327] Similarly, Geoffrey Marshall considers that a right bestows an entitlement to benefit from the performance of obligations,[328] while D. Galligan defines a right as a “justified claim that an interest should be protected by the imposition of correlative duties.”[329] According to these explanations, the holder of a right can have both a presumptive benefit—in the sense of an indefeasible or absolute, positive entitlement to a right, such as a right to equality—or protection—meaning a negative entitlement, such as a right not to be deprived of one’s freedom, or both. Moreover, the holder of the right can assert it against those who seek to curtail their exercise of it. While a right may be asserted expressly, it can also be implied on the basis that it is assumed that the holder of it would not want it to be infringed upon. By virtue of the fact that a right must be asserted or implied, the possessor of the right can also waive it.

Some philosophers who propound rights-based theories have already argued that animals have rights. For instance, according to Tom Regan, because animals, like humans, are the “subject of a life,”[330] they have inherent value and, therefore, also have the right not to be harmed, the right to aid if that right is violated, and the right to defend themselves.[331] Likewise, James Rachels maintains that animals that are used for research have the right not to be tortured,[332] and the right to liberty.[333]

Other philosophers have proposed certain preconditions to the holding of rights that, at first glance, seem to restrict their possession to humans. Yet, on closer examination, these arguments do not preclude the application of rights-based moral theories to animals. For instance, H. L. A. Hart maintains that, to have a right, the holder of it must be capable of electing whether or not to exercise it, which appears to restrict its application to humans.[334] Nevertheless, society recognizes that various classes of people, including young children and severely intellectually-disabled people, have rights regardless of the fact that they may not be able to choose whether to exercise them. In any event, many animals’ attempts to avoid pain can be interpreted as demonstrating that they have chosen to exercise their right to be free from cruelty. Any argument that the holder of a right must expressly elect to exercise it and that he or she cannot implicitly exercise it is indefensible, as it would mean that people could have their rights infringed upon when circumstances prevent them from exercising them, such as when they are asleep or unconscious.

Another philosopher, Michael Tooley, maintains that a right to life is only available to an entity that wishes to continue existing as a being that experiences life and particular mental states.[335] While, superficially, it might seem that only humans have a right to life on this account, as discussed above, scientists have observed that certain animals are aware of their ongoing existence, and therefore have a preference for living over dying, and some animals are conscious of their mental states.[336] Moreover, if we extrapolate Tooley’s prerequisites for the existence of the right to life to an examination of whether or not there is a specific right to be free from pain, for a being to enjoy this right, it would need to be capable of desiring the benefits that are consequent upon the exercise of that right.[337] As pain is, by its nature, undesirable, in light of scientific evidence that many animals experience pain, they would possess this right, too.

It is therefore clear that the definitions of rights that have been proposed do not preclude animals’ possession of them. Moreover, any definition of rights that seeks to confine their application to humans simply on the basis that they belong to a privileged class could be forcefully challenged on the basis that it is speciesist, that is, it favors humans over all other species.[338] Rachels believes that speciesism warrants receiving the same condemnation as racism and sexism.[339] Speciesism is particularly unjustifiable given that many animals share important human characteristics, including that they have a lifespan, thoughts, and emotions, and the cognitive functionality of some animals, such as dolphins, exceeds that of small children and severely intellectually-disabled people.[340] Especially significant is that, as we have discussed, scientific evidence confirms that animals can experience similar physical pain to humans, and some animals can suffer psychological harm, too. Michael Fox originally argued that only humans could belong to a “moral community,” which he defined as:

[A] social group composed of interacting autonomous beings where moral concepts and precepts can evolve and be understood. It is also a social group in which mutual recognition of autonomy and personhood exist.[341]

Fox claimed that animals were excluded from this community because they lacked self-awareness, the ability to accept responsibility for their actions, and the capacity to use sophisticated language.[342] Nevertheless, after acknowledging that some humans with limited cognitive abilities also did not share those traits, Fox retracted his former view and stated, “our basic moral obligations to avoid causing harm to other people should be extended to animals.”[343] Any other basis on which it is alleged that only humans can hold rights is as arbitrary a form of discrimination as the notion that belonging to a particular species is a precondition to possessing rights.

Rebutting the Use of Contractualist Moral Theories to Deny Animals Moral Status

Philosophers who subscribe to another influential stream of moral theories that focus on ideals rather than rights have denied that animals have moral standing. One of those theories is titled “contractualism,” which Peter Carruthers, a proponent of it, explains, “views morality as the result of an imaginary contract between rational agents, who are agreeing upon rules to govern their subsequent behavior.”[344] Carruthers argues that animals lack moral status for the reason that they cannot be classified as rational agents.[345] Although animals may have beliefs and desires, Carruthers considers that they lack other crucial preconditions of rational agency, namely, the capacity to conceptualize and follow general social rules, plan for the future, and conceive of different potential futures.[346] Another philosopher, John Rawls, who has developed a contractualist theory of justice, acknowledges that “it is wrong to be cruel to animals and the destruction of a whole species can be a great evil.[347] The capacity for feelings of pleasure and pain and for the forms of life of which animals are capable clearly imposes duties of compassion and humanity in their case.”[348] Yet Rawls also argues that only “moral persons,” whom he defines as those who are capable of conceiving of their own good based on their rational plans for life and sense of justice, are entitled to equal justice.[349] Consequently, Rawls believes that animals are “outside the scope of the theory of justice, and it does not seem possible to extend the contract doctrine so as to include them in a natural way.”[350]

Nevertheless, contractualism is inherently anthropocentric and speciesist. It is, therefore, unreasonable to rely on it to deny animals moral status. Moreover, if taken to its logical conclusion, its application would mean that some humans also lack moral standing, a notion that does not align with current social norms. Contractualism assesses whether entities have moral standing based exclusively on a capacity that only some humans—namely, adults with high cognitive capabilities—possess, that is, the ability to enter into a social contract.[351] According to this theory, animals are precluded from obtaining moral status, are morally inferior to humans, and cruelty towards them can be justified on this basis.[352] Yet, as Regan observes, this theory could equally be deployed to argue that some humans, such as young children and intellectually-disabled adults, lack moral status; they, too, cannot be described as rational agents if rational agents are defined as those who possess the capacity to enter into contracts.[353]

Conclusion Regarding Animals’ Moral Status

The above discussion confirms that the most persuasive reason for maintaining that animals have moral standing is that scientific investigation has proven that many animals are sentient and feel pain. Particularly from a consequentialist theoretical perspective, such as utilitarianism, this evidence confirms that animals have interests that must be factored into an assessment of the morality of any behavior towards them, with the overriding objective of maximizing happiness and reducing pain. Although non-consequentialist theories, and particularly rights-based theories, were not initially conceived to apply to animals, there is no definitional reason why they could not so apply. Moreover, attempts to restrict their application to humans could be discredited on the basis that they are unduly speciesist. As it is similarly speciesist and anthropocentric because it is based on characteristics possessed mainly by high-functioning humans, contractualism, therefore, also cannot be relied on to deny animals moral status.

Given the strong connection between the law and morality,[354] the finding that animals have moral standing provides an ethical justification for according their interests legal protection. Animals’ interests are, in some respects, different from those of humans, and the law must reflect those differences. It is unnecessary, for instance, to give animals the right to vote or own property. Nevertheless, as many animals, like humans, can feel pain, they equally have an interest in being free of it. Protection of this interest necessitates criminalizing acts that inflict pain on animals and punishing offenders who commit animal cruelty offenses to reflect the seriousness of this behavior.

Reform Recommendations

In this part of the Article, we provide a summary of our recommendations for changes to the law concerning animal cruelty offending by focusing first on the categorization of those offenses and then examining the sentencing of them. We conceive this proposal as a model for reform in all jurisdictions of the United States.

The Nature and Scope of Animal Cruelty Offenses

To ensure that acts of animal cruelty are criminalized appropriately and consistently, we propose the development of a classification of animal cruelty offenses. There are many different forms of human cruelty towards animals, and many different species of animals are victims of it. To determine which acts should be criminalized and which animals should be protected from human cruelty, we recommend that classification of these offenses draw on science, social norms, and moral philosophy. We now explain how each of these matters can inform this categorization.

Scientific research into animals’ physiology and psychology can help to identify the impact that human cruelty has on particular species of animals, and thus which acts should be penalized. As we have seen, scientific investigation has already established that many vertebrates, in particular, are capable of feeling physical pain.[355] Scientific research suggests that some animals, and particularly those with more advanced cognition, can also experience psychological harm.[356] As further scientific investigation uncovers with greater precision which animals can feel physical pain, the nature of the pain that they feel, and which animals are capable of experiencing psychological distress, this evidence should inform the human acts of cruelty towards animals that are categorized as crimes.

The extent to which scientific research influences the classification of animal cruelty offenses must nonetheless be subject to current normative values. If recommendations for reforms to this area of the law do not take into account present social norms concerning human interaction with animals, they may be completely disregarded. While substantial changes to the law might be considered ideal, it would be overly ambitious, impractical, and potentially self-defeating to propose them all at this point in time if they are likely to be rejected. History demonstrates that worthy legal developments often arise through a series of incremental shifts that occur in tandem with evolving social norms,[357] though they can shape those norms, too. For instance, while many would consider it logically and morally incontestable that African Americans should have the same rights and privileges as the rest of the community, it would have been futile to suggest in 1865, when slavery was abolished, that African Americans should receive full civil and social equality. In fact, African Americans were only accorded voting rights about fifty years ago.[358] Alarmingly, African Americans still experience significant discrimination and social and economic disadvantage.[359]

While the notion that humans should not cause animals to suffer accords with contemporary normative values, even if scientific evidence confirms that human cruelty towards animals induces such suffering, society will not accept that all behavior that has this outcome should be criminalized. It is crucial that any reform proposal acknowledges that many current popular social customs and practices in the United States involve animals, cause them some harm, and even kill them. At present, notwithstanding the growth of veganism, animals, and products derived from them, remain a dominant staple of many people’s diets. Billions of animals are killed annually for human consumption.[360] People continue to use animal products, such as leather and hide, to create clothing, accessories, and make-up. In addition, people enjoy sports that depend on animals’ involvement, including equestrian sports, and horse and dog racing. Circuses also use animals to perform tricks, and animals are kept in zoos for human observation. Many people fish and hunt animals, such as ducks, rabbits, deer, and birds, for entertainment and food. Certain animals, such as rabbits, are killed if they are deemed to be pests, for instance, to farmed crops. Scientific experiments are regularly conducted on animals in order to develop medical and other treatments for humans. Wholesale criminalization of these human interactions with animals would undoubtedly attract substantial opposition.

Nevertheless, the public would likely welcome measured reforms that penalize some human acts of cruelty that cause what is deemed to be gratuitous physical pain in or psychological harm to animals that have more advanced cognitive capacities and sentience in particular. People seem to hold greater respect for animals that demonstrate that they share, to some extent, human capacities of thinking and feeling. Therefore, while they might object to criminalizing an act of cruelty against an ant or slug, they would be open to penalizing such behavior towards a dog or monkey. It may, therefore, be impracticable at this point in time to contend that acts of cruelty towards invertebrates with less cognitive capacities and sentience than fish should be punished. In addition, society may deem some suffering inflicted upon animals to be necessary. For instance, it might be considered vital (though unfortunate) to cause significant pain to a small number of animals for the purpose of undertaking research to find a cure for human disease. Yet the public would probably recognize that it is possible for humans to continue depending on animals without inflicting undue suffering on them. If animals are killed for the purpose of using their bodies for scientific research, food, sport, or clothing, this can be performed swiftly to ensure that they experience minimal physical pain. Likewise, measures can be introduced into sports that involve animals so that they do not suffer unnecessarily from participating in them. The community would likely accept the imposition of penalties on people who do not take these steps to prevent certain animals’ undue suffering.

The appropriate definition of animal cruelty has long been the subject of debate among scholars, clinicians, and policymakers.[361] Yet many social scientists have adopted a definition proposed by Ascione in 1993, namely, that animal cruelty is “socially unacceptable behavior that intentionally causes unnecessary pain, suffering, or distress to and/or death of an animal.”[362] This definition is intended to encompass “cruelty that may be psychological in nature.”[363] In addition, it purposely excludes socially approved practices related to the treatment or use of animals in veterinary practices and livestock production or other animal husbandry practices and in hunting and in laboratory research,[364] which are also socially acceptable forms of animal cruelty.[365] We consider that it would align with current normative values to adapt this definition for use in legislation that criminalizes human cruelty towards animals.

Importantly, popular moral philosophy that informs social norms supports reforms to the law that would penalize acts of human cruelty towards vertebrates with high sentience that cause them to suffer physical or psychological pain. On the basis of consquentialist and non-consequentialist moral theories, it is clear that certain animals have moral standing, and therefore, their suffering as a consequence of human acts should be taken into account in determining whether that behavior is morally right or wrong and should be punished.

To summarize then, initial proposals for classification of animal cruelty offenses could focus on human behavior that causes unnecessary, significant physical pain in or psychological harm to vertebrates with high sentience whom scientific evidence has confirmed can feel such pain. Animals’ suffering that is deemed unnecessary might need to be determined on a case by case basis. These changes should penalize cruelty towards animals that are farmed and used in research, sport, and other entertainment, in addition to companion animals. Acts of cruelty toward animals that result in those animals’ death should be included in a classification of animal cruelty offenses where they have a traumatic impact on humans that have a relationship with those animals. A relation may exist, for example, if the animals are pets, the animals depended on the killed animals, or both.

It is likely that some human behavior that meets this broad definition of animal cruelty is currently socially accepted. Criminalization of some of this behavior could nonetheless raise awareness of its impact on sentient animals. We consider that further reform to animal cruelty law should be pursued in the future to criminalize a wider range of human behavior towards animals. Once initial changes are incorporated into existing laws, it will then be possible to make further incremental and meaningful reforms to animal cruelty law in a linear, ongoing manner, which reflect emerging scientific evidence about animals’ physiological and psychological constitution, and their experience of pain, as well as evolving social norms.

Calibration of Sanctions for Animal Cruelty Offenses

Sentencing jurisprudence has hitherto developed in relation to crimes that involve human victims. Nevertheless, this is not an impediment to establishing a model approach to sentencing for animal cruelty crimes. This is especially the case because, as we have discussed, animals can experience similar pain to humans; according to current social norms, it is inappropriate for humans to cause animals to suffer unnecessarily; and popular philosophical theories establish that animals, like humans, have moral status and therefore deserve legal protection from acts of cruelty. Moreover, it is fitting to apply the same sentencing objectives and principles that have proven effective in determining penalties for crimes committed against people to calibrating sanctions for animal cruelty offenses.

The sentencing objective of community protection might not intuitively seem relevant to crimes that are committed against animals. Nevertheless, as we have seen, animal cruelty offenders can pose a risk to the public. This is especially the case because, as research has established, there can be a strong connection between people’s acts of cruelty towards animals and their commission of offenses against other people.[366] In sentencing animal cruelty offenders, we, therefore, propose that courts should attempt to achieve the aim of community protection to some degree. We also consider that judges should focus on the sentencing objective of rehabilitation to the extent that an offender’s demonstration of a high probability of reform may constitute a mitigating factor. Yet the major principle that should inform sentencing of animal cruelty offenders is proportionality so that the severity of the sanctions that are imposed matches the seriousness of the crimes that they have committed.

In applying the principle of proportionality, it is important to assess the impact of an animal cruelty offense. To this end, it is telling that cruelty offenses constitute the gravest crime that can be committed against animals, and can be even more serious than killing them. Animals cannot necessarily communicate the suffering that acts of cruelty inflict on them in the same way as humans. Nevertheless, as we have seen, scientific investigation has confirmed that such acts can cause certain vertebrates to experience significant physical pain, which is similar to the pain felt by humans, and psychological harm.[367] The degree and duration of pain inflicted on an animal should inform the evaluation of the seriousness of the animal cruelty offense. For instance, an act of animal cruelty will be deemed especially grave if it causes the animal to suffer from pain that is intense, persistent, and endures for a long time.

Also, in calculating the gravity of an animal cruelty offense, it will be important for a court to begin by considering the sanction that would be imposed if an act of cruelty was committed against a human. Scientific evidence about the physiology of a dog, for instance, may indicate that, if it is beaten, the dog will experience the same degree of pain as a person who is the victim of the same crime. It is, however, too ambitious to suggest that the same punishment should be imposed for both acts. As we have noted, according to current normative values, while certain animals have moral status and their lives are intrinsically important, they are not regarded as being as sacred as humans’ lives. Consequently, society would accept that a penalty for an animal cruelty offense is calibrated by taking the sanction prescribed for an offense of cruelty against a human and discounting accordingly. The complex question that nonetheless arises concerns the extent of the discount that should be accorded to the sentence of the offender who is cruel to an animal. There is no clear answer to this question. Yet, for reforms relating to sentencing of animal cruelty offenses to be viable, it is important that the penalties imposed for them are meaningfully lower than those imposed for similar conduct against humans, but still substantial enough to reflect their seriousness. The harshness of the penalty imposed could then be adjusted to achieve the objective of community protection, and respond to any relevant aggravating and mitigating factors (such as an offender’s good prospects of rehabilitation).

The current sentencing system in the United States is overly punitive as a consequence of a misguided “tough-on-crime” approach that politicians, for decades, assumed was popular with voters.[368] The result of this policy is that the United States has the highest incarceration levels on Earth, and by a wide margin.[369] This trend is only now receding, reflected in a lowering of the prison population since 2013,[370] and a loose consensus emerging among both Republican and Democratic politicians that “tough-on-crime” is a flawed policy and a more evidence-based approach to crime and punishment is necessary.[371] However, excessively harsh penalties are often still imposed for a range of offenses.[372] If this approach persists, animal cruelty offenders should often receive lengthy prison terms in the order of five years and more. As we have seen, the maximum penalty for animal cruelty offenses in some jurisdictions already exceeds this level,[373] as does federal law,[374] and hence, there is certainly scope for courts to impose adequate penalties on animal cruelty offenders.

Nevertheless, if a more progressive approach to sentencing is adopted generally, which is driven primarily by the principle of proportionality, there will be a reduction in the harshness of penalties imposed for most offenses. In light of the recent lowering of prison numbers and political recognition that reform of sentencing law is essential, it is feasible that such a system could be introduced.[375] Pursuant to a model sentencing system, offenders who commit the most serious animal cruelty crimes might still receive prison sentences, but they would not need to be particularly lengthy given that research has shown that incarceration does not lower the rate of commission of crimes or recidivism.[376] We suggest the imposition of a maximum term of imprisonment of seven years, in line with the maximum sentence of imprisonment under the PACT Act, for the most grave animal cruelty offenses. This term could be increased to eight years if the crime results in the death of an animal that is aware of its ongoing existence and has a clear preference for remaining alive, if it causes distress to a human (most typically where the animal is a person’s pet), the suffering of another animal that depends on the animal that is killed (for example, where the animal that is killed was nurturing its offspring), or all of the above.

It could also be appropriate to place many offenders who commit animal cruelty offenses on probation for a period of up to two years. This court-imposed order mandating correctional supervision in the community is normally ordered as an alternative to incarceration,[377] and is harsher than a fine. Offenders who are placed on probation are normally subjected to a number of restrictions. The most important condition is that they not commit any further offenses.[378] Other requirements typically include geographical restrictions (for example, constraints on where an offender can reside and travel), behavioral restrictions, such as a prohibition on consuming drugs and alcohol,[379] and attendance at meetings with corrections officers who monitor the orders.[380]

In determining the appropriate penalty for animal cruelty offenses, it should not be relevant whether the animal is domesticated, wild, particularly vulnerable, or even destined for slaughter. All of these animals would experience the same level of pain regardless of their circumstances. This approach is, in fact, consistent with that adopted recently in New Zealand, which is one of the few countries where courts have considered the relevance of animals’ sentience to the sentencing calculus.[381]

For the purpose of determining the practical effect (if any) of animals’ sentience, the Court of Appeal in the case of Erickson v. Minister for Property Industries [2017][382] examined the brutal treatment of bobby calves by a casually-employed slaughterman. The defendant, Erickson, pleaded guilty to charges brought against him under sections 28(1)(d), 12(c), 28A(1)(d), 29(a), and 12(a) of the Animal Welfare Act 1999 (N.Z.).[383] These offenses included wilful ill-treatment of a calf with the result that it was seriously injured or impaired, killing a calf in such a manner that it suffered unreasonable or unnecessary pain or distress, reckless ill-treatment of calves with the result that they were seriously injured or impaired, and failure to meet their physical health and behavioral needs.[384] The court of appeal’s judgment was concerned with sentencing Erickson for these offenses, and more generally with giving sentencing courts guidance on the question of which considerations should determine the gravity of offending in cases of willful and reckless ill-treatment of animals.[385] The court noted that the vulnerability of animals is not an aggravating factor, because all animals are necessarily vulnerable in the face of human cruelty, and therefore, this is already factored into sentencing.[386] The court also held that the fact that animals are destined to be food products does not constitute a mitigating factor in sentencing animal cruelty offenders.[387]


Humans inflict an enormous amount of suffering on animals. Legislation in every American state prohibits acts of animal cruelty to varying degrees. Yet offenders can receive varied penalties for the same crimes in different states. This is not surprising, given that there is a lack of consistent definitions of animal cruelty, most definitions do not encompass the variety of acts of animal cruelty that are committed, and there is no developed or coherent jurisprudence about the objectives, principles, and other matters that should guide courts in their sentencing of animal cruelty offenders. This Article attempts to fill this void by proposing a model approach to classifying and sentencing animal cruelty offenses, which we consider should apply uniformly throughout the United States.

An ideal classification of animal cruelty offenses would refer to different forms of animal cruelty offending and criminalize behavior towards animals that causes animals to suffer unnecessarily. Further, it would not discriminate against animals on the basis of human-use typologies, but instead would include crimes against animals that are farmed and used in research, sport, and entertainment, as well as companion animals. Given that science has established that some animals, in particular, vertebrates, have greater sentience and capacity to feel pain than other animals, it would also distinguish between animals on the basis of sentience.

This proposed sentencing framework would not aim to achieve the objectives of general and specific deterrence, as both are unattainable through the imposition of harsher sanctions. The sentencing objective of rehabilitation may be pursued to the extent that an offender’s demonstration of his or her reasonable likelihood of reform may be a mitigating factor. Further, courts would attempt to achieve the sentencing aim of community protection to some degree, especially given that animal cruelty can potentially lead to and co-occur with commission of acts of cruelty against humans. In ascertaining appropriate penalties for animal cruelty offenses, the main determinant should be the principle of proportionality, which prescribes that the severity of the sanction should match the seriousness of the crime. The only manner in which to calculate this equation rationally, even in a crude way, is to ascertain the level of pain caused by animal cruelty offenses.

As we have seen, scientific research has confirmed that many vertebrates are capable of experiencing physical pain, which resembles the pain felt by humans, and psychological harm.[388] The poignancy of this pain cannot be discounted meaningfully by the fact that the pain is experienced by animals instead of humans. Also, as we have discussed, the notion that humans should not inflict suffering on animals unduly accords with current normative values and with moral theories pursuant to which it is apparent that animals, like humans, have moral standing. In light of this, conduct that subjects animals to significant suffering is particularly grave. The severity of an animal cruelty offense would be increased by the degree and duration of the pain that is inflicted on an animal. The gravity of an animal cruelty offense would be aggravated by the fact that it leads to the animal’s death if scientific evidence confirms that it is conscious of its ongoing existence and would clearly prefer to remain alive. Additionally, one must consider whether a human has a traumatic response to its death, its death leads to the extreme suffering of another animal that depends on it, or both. Therefore, this further suffering that may result from an act of animal cruelty needs to be factored into the overall harm caused by the offending.

As we have discussed, in proposing changes to animal cruelty laws, it is important initially to recommend measured reforms that are largely consistent with current social norms regarding humans’ interaction with animals. Once these changes are incorporated into existing laws, it will then be possible to make incremental adjustments, consistent with emerging evidence about animals’ capacities and with evolving social norms.

In concrete terms, we propose that animal cruelty offenses should be confined to acts that inflict physical or psychological pain on vertebrates, regardless of whether they are used by humans in some way. In the ideal sentencing system, the standard penalty that should be applied for offenses of this nature is probation of two years and, for more serious offenses, a prison sentence of between two and three years in length. These changes to the law would acknowledge animals’ moral status and the impact of cruelty offenses on them and harmonize this area of the law with scientific knowledge regarding the physiology and psychology of animals. Such a proposal would provide a basis for making further reforms in the future in response to emerging scientific research regarding animals’ sentience and developing normative values concerning humans’ interaction with animals.

  1. * Professor Mirko Bagaric, Director of the Evidence-Based Sentencing Project at Swinburne University, Melbourne.
  2. ** Dr. Jane Kotzmann, Lecturer, Deakin University, Melbourne.
  3. *** Associate Professor, Dr. Gabrielle Wolf, Deakin University, Melbourne.
  4. . 19 The Oxford English Dictionary 561 (J.A. Simpson & E.S.C. Weiner eds., 2d ed. 1989).
  5. . 2 The Shorter Oxford English Dictionary 1942 (C.T. Onions ed., 3d ed. 1973).
  6. . See Lynne U. Sneddon et al., Defining and Assessing Animal Pain, 97 Animal Behav. 201, 204 (2014).
  7. . See infra Part III.
  8. . See generally Jessica Eisen, Liberating Animal Law: Breaking Free from Human-Use Typologies, 17 Animal L. 59, 61–62 (2010) (describing the human-use paradigm).
  9. . See infra Part III.
  10. . See generally Anthony N. Doob & Cheryl Marie Webster, Sentence Severity and Crime: Accepting the Null Hypothesis, 30 Crime & Just. 143, 155–89 (2003) (reviewing empirical literature on the relationship between harsher criminal sentences and deterrence).
  11. . See Kate Stith & José A. Cabranes, Fear of Judging: Sentencing Guidelines in the Federal Courts 14 (1998).
  12. . See generally Paul H. Robinson & John M. Darley, Utility of Desert, 91 Nw. U. L. Rev. 453, 464–68 (1997) (suggesting that incapacitation theories of punishment are grounded in community protection goals).
  13. . Christopher Hensley et al., Exploring the Social and Emotional Context of Childhood Animal Cruelty and Its Potential Link to Adult Human Violence, 24 Psychol. Crime & L. 489, 497–98 (2018).
  14. . Mirko Bagaric, The Punishment Should Fit the Crime—Not the Prior Convictions of the Person That Committed the Crime: An Argument for Less Impact Being Accorded to Previous Convictions in Sentencing, 51 San Diego L. Rev. 343, 348 (2014).
  15. . See infra Part III.
  16. . See Sneddon et al., supra note 3.
  17. . See Franklin D. McMillan et al., Behavioral and Psychological Characteristics of Canine Victims of Abuse, 18 J. Applied Animal Welfare Sci. 92, 102–03 (2015) [hereinafter McMillan et al., Characteristics of Canine Victims]; Franklin D. McMillan, Behavioral and Psychological Outcomes for Dogs Sold as Puppies Through Pet Stores and/or Born in Commercial Breeding Establishments: Current Knowledge and Putative Causes, 19 J. Veterinary Behav. 14, 21–22 (2017) [hereinafter McMillan, Outcomes for Dogs].
  18. . See Mirko Bagaric, The “Civil-isation” of the Criminal Law, 25 Crim. L.J. 184, 187 (2001).
  19. . See id.
  20. . See Douglas A. Berman & Stephanos Bibas, Making Sentencing Sensible, 37 Ohio St. J. Crim. L. 37, 40–41 (2006); see also 6 Wayne R. LaFave et al., Criminal Procedure § 26.1(b) (4th ed. 2015).
  21. . See infra Part III.
  22. . See Stith & Cabranes, supra note 8, at 71.
  23. . See Kevin R. Reitz, Sentencing Guideline Systems and Sentence Appeals: A Comparison of Federal and State Experiences, 91 Nw. U. L. Rev. 1441, 1442 (1997).
  24. . See Berman & Bibas, supra note 17, at 40. There are more than 200,000 federal prisoners. See E. Ann Carson, Bureau of Justice Statistics, U.S. Dep’t of Justice, Prisoners in 2013, at 2 tbl.1 (2014),
    ty=pbdetail&iid=5109 []. Also, as noted below, the broad structure of the Federal Guidelines is similar to many other guideline systems in that the penalty range is not mandatory and permits departures in certain circumstances. See infra note 32 and accompanying text.
  25. . See Nat’l Research Council, Comm. on Causes and Consequences of the High Rates of Incarceration, The Growth of Incarceration in the United States: Exploring Causes and Consequences 62 (Jeremy Travis et al. eds., 2014).
  26. . Melissa Hamilton, Sentencing Disparities, 6 Brit. J. Am. Legal Stud. 176, 182 (2017).
  27. . Ames C. Grawert et al., A Federal Agenda to Reduce Mass Incarceration 1 (2017),
    %20agenda%20to%20reduce%20mass%20incarceration.pdf [].
  28. . See Carissa Byrne Hessick, Why Are Only Bad Acts Good Sentencing Factors?, 88 B.U. L. Rev. 1109, 1115 (2008).
  29. . See U.S. Sentencing Guidelines Manual § 4A1.1 (U.S. Sentencing Comm’n 2018).
  30. . Offense levels range from 1 (least serious) to 43 (most serious). Id. § 5A.
  31. . The criminal history score ranges from 0 (least offending record) to 13 or more (worst offending record). Id.
  32. . Id.
  33. . Amy Baron-Evans & Jennifer Niles Coffin, No More Math Without Subtraction: Deconstructing the Guidelines’ Prohibitions and Restrictions on Mitigating Factors, at i (rev. ed. 2011).
  34. . Id.
  35. . See U.S. Sentencing Guidelines Manual § 1B1.4 (U.S. Sentencing Comm’n 2018) (providing that a court may consider the defendant’s background in deciding whether to depart from the sentencing guidelines).
  36. . These are set out in Chapter 3 of the U.S. Sentencing Guidelines Manual. See id. § 3.
  37. . See id. § 3E1.1. However, § 5K2.0(d)(4) provides that the court cannot depart from a guideline range as a result of:The defendant’s decision, in and of itself, to plead guilty to the offense or to enter a plea agreement with respect to the offense (i.e., a departure may not be based merely on the fact that the defendant decided to plead guilty or to enter into a plea agreement, but a departure may be based on justifiable, non-prohibited reasons as part of a sentence that is recommended, or agreed to, in the plea agreement and accepted by the court.
  38. . See id. § 5K.
  39. . Id. ch.1, pt. A, introductory cmt.
  40. . Id. § 5K2.0(a)(2)(B); see also Pepper v. United States, 562 U.S. 476, 500 (2011); Gall v. United States, 552 U.S. 38, 38 (2007).
  41. . See U.S. Sentencing Guidelines Manual § 5K2.0(e).
  42. . See 18 U.S.C. § 3553(b)(1) (2018).
  43. . See United States v. Booker, 543 U.S. 220, 259 (2005) (excising the provision making the Guidelines mandatory as contrary to the Sixth Amendment right to a jury trial); see also Pepper, 562 U.S. at 481 (“[W]hen a defendant’s sentence has been set aside on appeal, a district court at resentencing may consider evidence . . . [that may] support a downward variance from the now-advisory Federal Sentencing Guidelines range.”); Irizarry v. United States, 553 U.S. 708, 715 (2008) (“[T]here is no longer a limit comparable to the one at issue in Burns on the variances from Guidelines ranges that a district court may find justified under the sentencing factors set forth in 18 U.S.C. § 3553(a).”); Gall, 552 U.S. at 41 (“[W]hile the extent of the difference between a particular sentence and the recommended Guidelines range is surely relevant, courts of appeals must review all sentences—whether inside, just outside, or significantly outside the Guidelines range—under a deferential abuse-of-discretion standard.”); Rita v. United States, 551 U.S. 338, 347 (2007) (holding that federal appellate courts may apply presumption of reasonableness to district court sentence that is within properly calculated Sentencing Guidelines range).
  44. . For example, 48.6% of sentences in 2016 fell within the guideline range, with a slight increase to 49.1% in 2017. U.S. Sentencing Comm’n, 2017 Annual Report (2017).
  45. . 18 U.S.C.A. § 48(a)(1), (f)(1) (Westlaw through Pub. L. No. 116-72).
  46. . Preventing Animal Cruelty and Torture (PACT) Act, Animal Welfare Inst., [].
  47. . 18 U.S.C.A. § 48(c).
  48. . Laws that Protect Animals, Animal Legal Def. Fund, [].
  49. . See discussion infra pp. 10–22.
  50. . Although we note that four of these five states are ranked as “Top Tier” and one is ranked as “Middle Tier” in the Animal Legal Defense Fund’s 2018 U.S. Animal Protection Laws State Rankings, this overview paints a more positive overall picture than a detailed analysis would depict. For the rankings of all fifty states, see Animal Legal Def. Fund, 2018 U.S. Animal Protection Laws State Rankings 7–8 (2018).
  51. . Cal. Penal Code § 599b (West, Westlaw through Ch. 870 of 2019 Reg. Sess.).
  52. . Id. § 597a (Westlaw).
  53. . Id. § 597b.
  54. . Id. § 597c.
  55. . Id. § 1170(h)(1).
  56. . Id. § 597d.
  57. . Id.
  58. . Tex. Penal Code § 42.09(b)(5)(A)–(D) (West, Westlaw through 2019 Reg. Sess.).
  59. . Id. § 42.09(a)(1)–(9) (Westlaw).
  60. . Id. § 42.09(c).
  61. . Id. § 12.21.
  62. . Id. § 42.09(c).
  63. . Id. § 12.35.
  64. . Id. § 42.092(b).
  65. . Id. § 42.092(a)(2).
  66. . Id. § 42.092(b)(1)–(9).
  67. . Id. § 42.092(c).
  68. . Id. § 12.21.
  69. . Id. § 42.092(c-1).
  70. . Id. § 12.34.
  71. . Id. § 42.092(c-2).
  72. . Id. § 12.35(a)–(b).
  73. . Fla. Stat. § 828.02 (West, Westlaw through 2019 First Reg. Sess.).
  74. . Id.
  75. . Id. § 828.12(1) (Westlaw).
  76. . Id.
  77. . Id. § 775.082(4)(a).
  78. . Id. § 828.12(1).
  79. . Id. § 828.12(2).
  80. . Id.
  81. . Id. § 775.082(3)(e).
  82. . Id. § 828.12(2).
  83. . N.Y. Agric. & Mkts. Law § 350(1) (McKinney, Westlaw through L.2019, ch. 74).
  84. . Id. § 350(2) (Westlaw).
  85. . Id. § 353.
  86. . Id.; N.Y. Penal Law § 70.15(1) (McKinney, Westlaw through L.2019, ch. 74).
  87. . N.Y. Penal Law § 80.05(1) (Westlaw).
  88. . Id.
  89. . N.Y Agric. & Mkts. Law § 353-a(1) (Westlaw).
  90. . Id. § 353-a(1).
  91. . Id. § 353-a(3); N.Y. Penal Law §§ 55.10(1)(b), 80.00(1)(a) (Westlaw).
  92. . 510 Ill. Comp. Stat. 70/2.01 (West, Westlaw through P.A. 101–592).
  93. . Id. 70/2.01(a) (Westlaw).
  94. . Id. 70/3.01(a), (d).
  95. . Id. 70/3.01(d); 730 Ill. Comp. Stat. 5/5-4.5-55(a), (e) (Westlaw).
  96. . 510 Ill. Comp. Stat. 70/3.02(c) (Westlaw); 730 Ill. Comp. Stat. 5/5-4.5-45 (a), (e), -50(b) (Westlaw).
  97. . 510 Ill. Comp. Stat. 70/3.02(a) (Westlaw).
  98. . Id. § 70/3.03(a).
  99. . Id.
  100. . Id. § 70/3.03(c); 730 Ill. Comp. Stat. 5/5-4.5-40(a), (e), -50(b) (Westlaw).
  101. . Compare Tex. Penal Code Ann. §§ 42.09(a)(5), (d)–(f) (West, Westlaw through 2019 Reg. Sess.), and id. §§ 42.092(a)(2), (d)–(f) (Westlaw), with Cal. Penal Code § 597(e) (West, Westlaw through Ch. 870 of 2019 Reg. Sess.), and Fla. Stat. § 828.02 (West, Westlaw through 2019 First Reg. Sess.), and 510 Ill. Comp. Stat. 70/2.01 (Westlaw), and N.Y. Agric. & Mkts. Law § 350(1) (McKinney, Westlaw through L.2019, ch. 74).
  102. . Hensley et al. supra note 10, at 498.
  103. . See supra Section II.B.1.
  104. . See id.
  105. . 18 U.S.C.A. § 48(f)(1) (Westlaw through Pub. L. No. 116-72).
  106. . See id.
  107. . See Jessica Eisen, Liberating Animal Law: Breaking Free from Human-Use Typologies, 17 Animal L. 59, 60 (2010).
  108. . See supra Section II.B.1.d.
  109. . People v. Tom, 231 Cal. Rptr. 3d 350, 351–52 (Ct. App. 2018).
  110. . Id. at 352.
  111. . People v. Burnett, 2 Cal. Rptr. 3d 120, 123 (Ct. App. 2003).
  112. . Id. at 125.
  113. . People v. Youngblood, 109 Cal. Rptr. 2d 776, 778 (Ct. App. 2001).
  114. . Id. at 777.
  115. . People v. Sanchez, 114 Cal. Rptr. 2d 437, 440 (Ct. App. 2001).
  116. . Id.
  117. . Id. at 443. On appeal, six counts of the defendant’s convictions were affirmed. See id. at 448. Each violation is punishable by a maximum term of imprisonment of three years, or by a fine of not more than $20,000, or by both fine and imprisonment. Cal. Penal Code §§ 597(d), 1170(h) (West, Westlaw through Ch. 870 of 2019 Reg. Sess.).
  118. . People v. Baniqued, 101 Cal. Rptr. 2d 835, 837 (Ct. App. 2000).
  119. . Id.
  120. . Id.
  121. . People v. Williams, 222 Cal. Rptr. 3d 806, 814 (Ct. App. 2017). On appeal, the defendants’ convictions were affirmed. Id. at 819. See generally Cal. Penal Code §§ 597.5(a)(1), 597(b) (Westlaw) (codifying the felony of dogfighting and the felony of animal cruelty).
  122. . 222 Cal. Rptr. 3d at 814.
  123. . Id.
  124. . Justice v. State, 532 S.W.3d 862, 864 (Tex. Crim. App. 2017).
  125. . Id. On appeal, the case was remanded for a new hearing on punishment only after deleting the deadly weapon finding. Id. at 866. See generally Prichard v. State, 533 S.W.3d 315 (Tex. Crim. App. 2017) (holding that a deadly weapon finding is disallowed when the victim is nonhuman).
  126. . Amos v. State, 478 S.W.3d 764, 767 (Tex. Crim. App. 2015). The lower court’s decision was affirmed on appeal. Id. at 773.
  127. . Id. at 767 n.1.
  128. . Id.
  129. . Id. at 767.
  130. . Swilley v. State, 465 S.W.3d 789, 790 (Tex. Crim. App. 2015). The conviction was affirmed on appeal. Id. at 797.
  131. . Galindo v. State, 564 S.W.3d 223, 224 (Tex. Crim. App. 2018).
  132. . Dixon v. State, 455 S.W.3d 669, 672 (Tex. Crim. App. 2014). The Court of Appeals of Texas affirmed the trial court’s ruling. Id. at 684.
  133. . Id. at 672.
  134. . Id. at 673–74.
  135. . Id.
  136. . Id. at 672. This offense is punishable by imprisonment for a maximum of ten years and a fine of up to $10,000. Tex. Penal Code Ann. §§ 12.35(c)(2)(B), 42.092(c) (West, Westlaw through 2019 Reg. Sess.).
  137. . Brown v. State, 166 So. 3d 817, 818 (Fla. Dist. Ct. App. 2015).
  138. . Id. at 820.
  139. . Id. at 818.
  140. . Bartlett v. State, 929 So. 2d 1125, 1126 (Fla. Dist. Ct. App. 2006).
  141. . Id.
  142. . Id.
  143. . Id.
  144. . People v. Garcia, 812 N.Y.S.2d 66, 68, 73 (App. Div. 2006).
  145. . Id. at 73.
  146. . People v. Degiorgio, 827 N.Y.S.2d 342, 344 (App. Div. 2007).
  147. . Id.
  148. . Id. at 343–44. A violation of this provision is a felony and carries a penalty of a term of imprisonment of no more than two years. N.Y. Agric. & Mkts. Law § 353-a(3) (McKinney, Westlaw through L.2019, ch. 74).
  149. . People v. Richardson, 66 N.Y.S.3d 757, 758, 760 (N.Y. App. Div. 2017) (affirming the defendant’s convictions and sentence). See generally N.Y. Agric. & Mkts. Law §§ 351(2), 351(6), 353 (Westlaw) (codifying felony animal fighting, misdemeanor animal fighting, and cruelty to animals as criminal offenses).
  150. . 66 N.Y.S.3d at 758.
  151. . Id. at 760.
  152. . Katie Alexander, Convicted Animal Abuser Sentenced to up to Eight Years in Prison, WIVB4 (Sep. 1, 2015), [].
  153. . People v. Lohnes, 976 N.Y.S.2d 719, 721 (N.Y. App. Div. 2013).
  154. . Id. at 721.
  155. . People v. Land, 955 N.E.2d 538, 542 (Ill. App. Ct. 2011). The Appellate Court of Illinois, First District, Sixth Division affirmed the convictions. Id. at 541.
  156. . Id. at 541. The offense is punishable by a maximum term of imprisonment of six years and a maximum fine of $25,000. 510 Ill. Comp. Stat. 70/3.02(c) (West, Westlaw through P.A. 101–592); 730 Ill. Comp. Stat. 5/5-4.5-45(a), (e) (Westlaw); id. 5/5-4.5-50(b).
  157. . People v. Robards, 97 N.E.3d 600, 601 (Ill. App. Ct. 2018).
  158. . Id. at 602.
  159. . Id. at 601.
  160. . Id.
  161. . Id. at 602.
  162. . Id.
  163. . Id. at 604.
  164. . Id. at 604–05.
  165. . See supra Section II.C.1.
  166. . See supra Section II.C.1.
  167. . See supra Section II.C.1.
  168. . See supra Section II.C.1.
  169. . Mirko Bagaric et al., Mitigating America’s Mass Incarceration Crisis Without Compromising Community Protection: Expanding the Role of Rehabilitation in Sentencing, 22 Lewis & Clark L. Rev. 1, 33 (2018).
  170. . See Richard Berk, New Claims About Executions and General Deterrence: Deja Vu All Over Again?, 2 J. Empirical Legal Stud. 303, 327–28 (2005); Dale O. Cloninger & Roberto Marchesini, Execution and Deterrence: A Quasi-Controlled Group Experiment, 33 Applied Econ. 569, 574–75 (2001); Doob & Webster supra note 7, at 143–45; Steven D. Levitt, Understanding Why Crime Fell in the 1990s: Four Factors that Explain the Decline and Six that Do Not, 18 J. Econ. Persp. 163, 178 (2004); Paul R. Zimmerman, State Executions, Deterrence, and the Incidence of Murder, 7 J. Applied Econ. 163, 187–88 (2004).
  171. . See Bagaric supra note 11, at 402, 405–11.
  172. . See Pew Charitable Trusts, More Imprisonment Does Not Reduce State Drug Problems 5 (2018).
  173. . Id.
  174. . See Daniel S. Nagin et al., Imprisonment and Reoffending, 38 Crime & Just. 115, 124 (2009).
  175. . See Donald P. Green & Daniel Winik, Using Random Judge Assignments to Estimate the Effects of Incarceration and Probation on Recidivism Among Drug Offenders, 48 Criminology 357, 382 (2010).
  176. . See id. at 382–83; Donald Ritchie, Does Imprisonment Deter? A Review of the Evidence 18, 21 (2011); New South Wales Law Reform Comm’n, Rep. No. 139, Sentencing 3 (2013); Franklin E. Zimring & Gordon J. Hawkins, Deterrence: The Legal Threat in Crime Control 245 (1973); Don Weatherburn et al., The Specific Deterrent Effect of Custodial Penalties on Juvenile Re-Offending, Crime & Just. Bull., July 2009, at 5.
  177. . See Bagaric, supra note 11, at 401–02.
  178. . See id. at 410–11.
  179. . Hensley et al., supra note 10, at 498.
  180. . Frank R. Ascione et al., Battered Pets and Domestic Violence: Animal Abuse Reported by Women Experiencing Intimate Violence and by Nonabused Women, 13 Violence Against Women 354, 355, 364 (2007).
  181. . Mark R. Dadds et al., Associations Among Cruelty to Animals, Family Conflict, and Psychopathic Traits in Childhood, 21 J. Interpersonal Violence 411, 411–12 (2006).
  182. . See Ascione et al., supra note 177, at 355; Hensley et al., supra note 10.
  183. . Piers Beirne, From Animal Abuse to Interhuman Violence? A Critical Review of the Progression Thesis, 12 Soc’y & Animals 39, 39–40 (2004); Dadds et al., supra note 178, at 412.
  184. . C. Longobardi & L. Badenes-Ribera, The Relationship Between Animal Cruelty in Children and Adolescent and Interpersonal Violence: A Systematic Review, 46 Aggression & Violent Behav. 201, 202 (2019).
  185. . See id.; Beirne, supra note 180, at 40.
  186. . See Beirne, supra note 180, at 46.
  187. . See Linda Merz-Perez et al., Childhood Cruelty to Animals and Subsequent Violence Against Humans, 45 Int’l J. Offender Therapy & Comp. Criminology 556, 569 (2001); Hensley et al., supra note 10, at 489.
  188. . For instance, in 1987, A. Felthous and S. Kellert published the results of their meta-analysis of fifteen studies of the association between childhood animal cruelty and adult interpersonal violence: five studies found a clear link between them, while ten did not. Nevertheless, the five studies used direct interviews, while the other ten used chart reviews. Further, the five studies defined the terms “animal cruelty” and “personal aggression” and used “recurrent acts of animal cruelty” and personal aggression, whereas the other ten did not define behaviors, and “used one act of animal abuse as animal cruelty” and “one act of violence to humans as personal aggression.” See Christopher Hensley et al., The Predictive Value of Childhood Cruelty Methods on Later Adult Violence: Examining Demographic and Situational Correlates, 56 Int’l J. Offender Therapy & Comp. Criminology 281, 282 (2012); Longobardi & Badenes-Ribera, supra note 181, at 202. In 2004, Piers Beirne claimed that the progression thesis was unsupported by empirical evidence given the lack of government and police-based data on animal abuse and prospective, longitudinal studies of this theory. See Beirne, supra note 180, at 41, 52–53. While such studies would undoubtedly be useful, subsequent studies have substantiated earlier research regarding this connection. See Hensley et al., supra note 185, at 287.
  189. . See Hensley et al., supra note 10, at 491; Hensley et al., supra note 185, at 293.
  190. . See Anne M. Volant et al., The Relationship Between Domestic Violence and Animal Abuse: An Australian Study, 23 J. Interpersonal Violence 1, 15 (2008).
  191. . Merz-Perez et al., supra note 184, at 558–60.
  192. . Id. at 561, 570.
  193. . Id. at 564, 567–68.
  194. . Hensley et al., supra note 185, at 285, 287.
  195. . See id. at 287–93.
  196. . Longobardi & Badenes-Ribera, supra note 181, at 202–03.
  197. . Id. at 208–09.
  198. . Id.
  199. . Id. at 202.
  200. . See id.
  201. . See id. at 207–08.
  202. . See Ascione et al., supra note 177, at 355; Beirne, supra note 180, at 41–42.
  203. . See Ascione et al, supra note 177, at 356–58; Volant et al., supra note 187, at 2.
  204. . Ascione et al., supra note 177, at 365.
  205. . Volant et al., supra note 187, at 15.
  206. . See id. at 5–6, 7, 9, 12.
  207. . See  C. L. TenCrime, Guilt and Punishment: A Philosophical Introduction 7 n.1, 8 (1987) (describing that an offender has undergone rehabilitation if he stops committing crime after serving a sentence because he now believes that the criminal behavior is wrong).
  208. . Richard G. Fox, The Meaning of Proportionality in Sentencing, 19 Melbourne U. L. Rev. 489, 490 (1994).
  209. . Id. at 491.
  210. . Id.
  211. . Id.
  212. . Id.
  213. . E. Thomas Sullivan & Richard S. Frase, Proportionality Principles in American Law: Controlling Excessive Government Actions 154 (2009); see also Gregory S. Schneider, Sentencing Proportionality in the States, 54 Ariz. L. Rev. 241 (2012) (focusing on the operation of the principle in Illinois, Oregon, Washington, and West Virginia).
  214. . See U.S. Sentencing Guidelines Manual, supra note 26, at ch. 1, pt. A, introductory cmt. (U.S. Sentencing Comm’n 2018).
  215. . Sullivan & Frase, supra note 210, at 154–55.
  216. . Id. at 154.
  217. . Jesper Ryberg, The Ethics of Proportionate Punishment: A Critical Investigation 184 (2004).
  218. . See id.
  219. . See id. at 61 (discussing that a crime may affect dimensions other than a person’s physical integrity, such as his or her freedom from humiliation).
  220. . See Kumar Amarasekara & Mirko Bagaric, Euthanasia, Morality and the Law 55–56 (2002).
  221. . See id. at 59 (discussing that humans respect the value of their own lives).
  222. . See generally Colin Allen & Michael Trestman, Animal Consciousness, Stan. Encyclopedia Phil. (Oct. 24, 2016), [] (exploring self-awareness and the ability to plan for the future in various species of animals).
  223. . Charles Darwin, Descent of Man 101 (1871).
  224. . Univ. of Iowa, Baboons And Pigeons Are Capable Of Higher-Level Cognition, Behavioral Studies Show, Sci. Daily (Feb. 16, 2009),
  225. . See generally Allen & Trestman, supra note 219 (exploring different studies that indicate an animal’s sense of awareness and self-consciousness).
  226. . See Allen & Trestman, supra note 219 (summarizing a collection of mirror studies completed with a variety of animals); Abigail Z. Rajala et al., Rhesus Monkeys (Macaca mulatta) Do Recognize Themselves in the Mirror: Implications for the Evolution of Self-Recognition, 5 PLOS ONE 1, 1 (2010),
    one/article/file?id=10.1371/journal.pone.0012865&type=printable [].
  227. . Rajala et al., supra note 223.
  228. . See id.
  229. . J. David Smith, The Study of Animal Metacognition, 13 Trends Cognitive Sci. 389 (2009).
  230. . See id. at 389.
  231. . See id. at 389, 391, 394.
  232. . Peter Singer, Practical Ethics 110–17 (2d ed. 1991).
  233. . Gerald H. Gosse & Michael J. Barnes, Human Grief Resulting from the Death of a Pet, 7 Anthrozoos 103, 103 (1994); Kenneth M. G. Keddie, Pathological Mourning After the Death of a Domestic Pet, 131 Brit. J. Psychiatry 21, 22 (1977).
  234. . Keddie, supra note 230, at 21.
  235. . Gosse & Barnes, supra note 230.
  236. . Id.
  237. . Id. at 110.
  238. . Keddie, supra note 230, at 21.
  239. . See discussion infra Section IV.A.1.
  240. . See discussion infra Section IV.A.2.
  241. . See discussion infra Section IV.B.
  242. . See discussion infra Section IV.C.
  243. . See Hope Ferdowsian & Debra Merskin, Parallels in Sources of Trauma, Pain, Distress, and Suffering in Humans and Nonhuman Animals, 13 J. Trauma & Dissociation 448, 449 (2012).
  244. . Id. at 461.
  245. . See, e.g., McMillan et al., Characteristics of Canine Victims, supra note 14; McMillan, Outcomes for Dogs, supra note 14.
  246. . “Anthropomorphism” is the term used to describe the practice of humans imposing human characteristics on their perception of animals and their behavior. Examples of anthropomorphic conduct are (i) a human pet “owner” referring to their pet cat’s paws as “hands”; (ii) if the pet cat becomes a little aggressive when being fed, their human owner may say “mind your manners Doris!” (Doris being the name of the human’s pet cat); or (iii) a human medical researcher thinking a research animal (like a mouse) is not feeling pain whilst the researcher is performing a certain procedure on that animal because the researcher feels that any human patient would not feel pain during such a procedure.
  247. . Daniel M. Weary et al., Identifying and Preventing Pain in Animals, 100 Applied Animal Behav. Sci. 64, 65 (2006).
  248. . Id. at 69.
  249. . Lynne U. Sneddon, Can Animals Feel Pain, Wellcome Trust, [].
  250. . David DeGrazia & Andrew Rowan, Pain, Suffering, and Anxiety in Animals and Humans, 12 Theoretical Med. 193, 197 (1991).
  251. . See id. at 197–98.
  252. . Hilde Vermeirsch et al., Evaluation of Pain Behavior and Bone Destruction in Two Arthritic Models in Guinea Pig and Rat, 87 Pharmacology Biochemistry & Behav. 349, 357 (2007).
  253. . John V. Roughan & Paul A. Flecknell, Evaluation of a Short Duration Behaviour-Based Post-Operative Pain Scoring System in Rats, 7 Eur. J. Pain 397, 405 (2005).
  254. . Johannes P.A.M. van Loon, et al., Application of a Composite Pain Scale to Objectively Monitor Horses with Somatic and Visceral Pain Under Hospital Conditions, 30 J. Equine Veterinary Sci. 641, 641 (2010); see P.D. McGreevy, Guest Editorial, The Fine Line Between Pressure and Pain: Ask the Horse, 188 Veterinary J. 250, 250 (2011).
  255. . See M.J. Gentle, Attentional Shifts Alter Pain Perception in the Chicken, 10 Animal Welfare S187, S192 (Supp. 2001), discussed in Daniel M. Weary et al., supra note 244, at 73; see also Andrew D. Fisher, Addressing Pain Caused by Mulesing in Sheep, 135 Applied Animal Behav. Sci. 232, 232 (2011) (indicating pain in sheep caused by mulesing procedure); S. Lomax et al., Use of Local Anaesthesia for Pain Management During Husbandry Procedures in Australian Sheep Flocks, 86 Small Ruminant Res. 56, 56 (2009) (finding pain in lambs caused by mulesing, castration, tail-docking, and ear-knotching procedures); K.M.D. Rutherford, Assessing Pain in Animals, 11 Animal Welfare 31, 36 (2002) (describing behavioral responses to pain in steers after branding and in calves after castration); Kevin J. Stafford & David J. Mellor, Addressing the Pain Associated with Disbudding and Dehorning in Cattle, 135 Applied Animal Behav. Sci. 226, 226 (2011) (observing pain in cattle caused by disbudding and dehorning procedures); Ignacio Vinuela-Fernandez et al., Pain Mechanisms and Their Implication for the Management of Pain in Farm and Companion Animals, 174 Veterinary J. 227, 231 (2007) (indicating ability of farm animals to feel pain); Kristen A. Walker et al., Identifying and Preventing Pain During and After Surgery in Farm Animals, 135 Applied Animal Behav. Sci. 259, 259 (2011) (identifying surgical pain in farm animals); Amy Simon, Tail Docking and Castration of Lambs, One Welfare (2003), [].
  256. . Sneddon, supra note 246; see also Lynne U. Sneddon et al., Do Fishes Have Nociceptors? Evidence for the Evolution of a Vertebrate Sensory System, 270 Proc. Royal Soc’y London B. 1115, 1115 (2003) (providing evidence of nociception in teleost fishes). Sømme claims that some invertebrates may be sentient and might feel pain. Lauritz S. Sømme, Sentience and Pain in Invertebrates: Report to the Norwegian Scientific Committee for Food Safety 14, 26–27, 35–37 (2005).
  257. . See K.P. Chandroo et al., Can Fish Suffer?: Perspectives on Sentience, Pain, Fear and Stress, 86 Applied Animal Behav. Sci. 225, 225 (2004) (suggesting fish can experience affective states of pain, fear, and stress); see also Victoria Braithwaite, Do Fish Feel Pain? 183 (2010) (concluding that fish feel pain); Lynne U. Sneddon, Nociception or Pain in Fish, in Encyclopedia of Fish Physiology: From Genome to Environment 714 (Anthony P. Farrell ed., 2011) (discussing potential for pain in fish); E. Lambooij et al., Welfare Aspects of Live Chilling and Freezing of Farmed Eel (Anguilla Anguilla L.): Neurological and Behavioural Assessment, 210 Aquaculture 159, 166 (2002) (observing responses to pain stimuli in eels); Ángel A. Rivas-Boyero et al., Pharmacological Characterization of a Nociceptin Receptor from Zebrafish (Danio Rerio), 46 J. Molecular Endocrinology 111, 112 (2011) (noting pain in zebrafish); Jonathan A.C. Roques et al., Tailfin Clipping, a Painful Procedure: Studies on Nile Tilapia and Common Carp, 101 Physiology & Behav. 533, 533 (2010) (observing pain in common carp and Nile tilapia); Lynne U. Sneddon, Assessing Pain Perception in Fish from Physiology to Behaviour, 146 Comp. Biochemistry & Physiology S75, S78 (Supp. 2007) (finding altered brain activity in carp after painful stimulation). One of the earlier studies to show responses in invertebrates to pain was that of Fiorito. See G. Fiorito, Is There “Pain” in Invertebrates?, 12 Behav. Processes 383, 386 (1986) (concluding that invertebrates possess a pain system); see also Stuart Barr et al., Nociception or Pain in a Decapod Crustacean?, 75 Animal Behav. 745, 749–50 (2008) (asserting that prolonged rubbing and grooming are consistent with the idea of pain in crustaceans); Colin Barras, Crustacean ‘Pain Response’ Gives Food for Thought, New Scientist, Nov. 10, 2007, at 14, 14; Robert W. Elwood et al., Pain and Stress in Crustaceans?, 118 Applied Animal Behav. Sci. 128, 134 (2009) (stating that crustaceans may experience pain).
  258. . Sneddon, supra note 246.
  259. . Id.
  260. . See supra text accompanying notes 243–48.
  261. . “Unless there is evidence to the contrary, it must be assumed that procedures and conditions that would cause pain and distress in humans cause pain and distress in animals.” Nat’l Health and Med. Research Council, Australian Code for the Care and Use of Animals for Scientific Purposes §§ 1.10, 3.3.1–6 (8th ed. 2013).
  262. . See Rashmi Shivni. It Doesn’t Have to Hurt: Recently Updated Guidelines Seek to Improve Pain Management in Small Animals, J. Am. Veterinary Med. Ass’n, Oct. 14, 2015, []; see also Am. Veterinary Med. Ass’n, AVMA Guidelines for the Euthanasia of Animals 7 (2013) (recommending euthanasia when animals’ lives no longer have positive net value).
  263. . Sarah Wolfensohn & Maggie Lloyd, Handbook of Laboratory Animal Management and Welfare 176–79 (1994); Patrick Bateson, Assessment of Pain in Animals, 42 Animal Behav. 827, 834 (1991); Lucia Martini et al., Evaluation of Pain and Stress Levels of Animals Used in Experimental Research, 88 J. Surgical Res. 114, 116–17 (2000); Roughan & Flecknell, supra note 250, at 403 tbl.2, 404 tbl.3.
  264. . David DeGrazia & Andrew Rowan, Pain, Suffering, and Anxiety in Animals and Humans, 12 Theoretical Med. 193, 193 (1991).
  265. . Klaus Wilhelm, Do Animals Have Feelings?, Sci. Am. Mind, Feb.–Mar. 2006, at 26, 26.
  266. . Ferdowsian & Merskin, supra note 240, at 461.
  267. . Id.
  268. . Marcus Dunk, A Mother’s Grief: Heartbroken Gorilla Cradles Her Dead Baby, Daily Mail (Aug. 19, 2008), [].
  269. . Wilhelm, supra note 262, at 29.
  270. . Ferdowsian & Merskin, supra note 240, at 453.
  271. . See Allen & Trestman, supra note 219.
  272. . Wilhelm, supra note 262, at 27 (citing Antonio R. Damasio, Looking for Spinoza 43–46 (2003)).
  273. . “Dominant gorillas swagger around to demand respect from their peers. Low-ranking wolves in packs make gestures of abasement. Dogs reprimanded by their owners for doing something wrong show clear signals of embarrassment. Yet even in such cases, as with primary emotions, some neuroscientists say these actions are largely automatic and inborn and count them among the routinized mechanisms animals use to help them survive.” Wilhelm, supra note 262, at 27–28.
  274. . Id. at 28–29.
  275. . Id. at 29.
  276. . Shreya Dasgupta, Many Animals Can Become Mentally Ill, BBC (Sept. 9, 2015), [].
  277. . Franklin D. McMillan, Psychological Trauma in Animals: PTSD and Beyond, Int’l Ass’n Animal Behav. Consultants, no. 1, 2011, at 107, 107; see also Marc Bekoff, Animals Don’t Laugh, Think, Get Depressed, or Love Declares a Psychiatrist, Psychol. Today (Sept. 3, 2012), []; Marc Bekoff, Do Wild Animals Suffer From PTSD and Other Psychological Disorders?, Psychol. Today (Nov. 29, 2011), [].
  278. . Hope R. Ferdowsian et al., Signs of Generalized Anxiety and Compulsive Disorders in Chimpanzees, 7 J. Veterinary Behav. 353, 360 [hereinafter Ferdowsian, Generalized Anxiety]; Hope R. Ferdowsian et al., Signs of Mood and Anxiety Disorders in Chimpanzees, PLOS ONE, June 2011, at 1, 9 [hereinafter Ferdowsian et al., Signs of Mood and Anxiety Disorders].
  279. . McMillan, supra note 274, at 107, 109.
  280. . See id. at 107.
  281. . Ferdowsian, Generalized Anxiety, supra note 275; Chimps Used in Experiments Develop Psychological Disorders, Arcus Found. (June 11, 2008),
    op-psychological-disorders/ [].
  282. . McMillan, Outcomes for Dogs, supra note 14, at 14.
  283. . Id.
  284. . McMillan, supra note 274, at 110; see also Jessica Pierce, Emotional Pain in Animals: An Invisible World of Hurt, Psychol. Today (Apr. 24, 2012), [] (discussing types of emotional abuse from which animals suffer).
  285. . Bagaric, supra note 15.
  286. . For example, Donnelly claims that there are three broad schools regarding the relative or comparative value of man and animals. One extreme proposes animals have “no inherent value” at all and this is based on the primacy of human welfare and scientific progress. Strachan Donnelly, Speculative Philosophy, the Troubled Middle, and the Ethics of Animal Experimentation, Hastings Ctr. Rep., Mar.–Apr. 1989, at 15, 15. At the other extreme there are antivivisectionists and animal rights advocates who claim that “certain animals, if not all life, have an ethical significance comparable” to that of humans. Id. Then in the middle is the third school which not only finds an “inherent goodness in organic life and concrete values” in individual animals, but concurrently also believes in the “goodness and value of human life.” Id.
  287. . See id. at 21.
  288. . Stephen O’ Sullivan & Philip A. Pecorino, Ethics: An Online Textbook ch. 4, § 3 (2009) (ebook).
  289. . L. W. Sumner, The Moral Foundation of Rights 165 (1987).
  290. . Id.
  291. . Mirko Bagaric & Penny Dimopoulos, International Human Rights Law: All Show, No Go, 4 J. Hum. Rts. 1, 12 (2005).
  292. . Mirko Bagaric, A Utilitarian Argument: Laying the Foundation for a Coherent System of Law, 10 Otago L. Rev. 163, 167 (2002).
  293. . Id.
  294. . Id. at 167, 175.
  295. . H. J. McCloskey, Meta-Ethics and Normative Ethics 180–81 (1969).
  296. . Robert Nozick, Anarchy, State, and Utopia 206 (1974).
  297. . Bagaric & Dimopoulos, supra note 288, at 13.
  298. . “[I]t has been argued that in fact rights do have a place in a utilitarian ethic, and what is more, it is only against this background that rights can be explained and their source justified. Utilitarianism provides a [sounder] foundation for rights than any other competing theory. For the utilitarian, the answer to why rights exist is simple: recognition of them best promotes general utility. Their origin accordingly lies in the pursuit of happiness. Their content is discovered through empirical observations regarding the patterns of behavior [that] best advance the utilitarian cause.” Bagaric & Dimopoulos, supra note 288, at 14.
  299. . John Rawls, A Theory of Justice 24, 163 (Harvard Univ. Press rev. ed. 1999).
  300. . Sumner, supra note 286.
  301. . O’ Sullivan & Pecorino, supra note 285.
  302. . See id. at ch. 7, § 1.
  303. . See id.
  304. . Mirko Bagaric, In Defence of a Utilitarian Theory of Punishment: Punishing the Innocent and the Compatibility of Utilitarianism and Rights, 24 Australian J. L. Phil. 95, 123 (1999).
  305. . Bagaric & Dimopoulos, supra note 288, at 6.
  306. . See Bagaric, supra note 301, at 99.
  307. . Sumner, supra note 286, at 1 (“[T]he escalation of rights rhetoric is out of control.”).
  308. . Id.
  309. . H. L. A. Hart, Utilitarianism and Natural Rights, in Essays in Jurisprudence and Philosophy 181, 196–97 (1983).
  310. . Tom D. Campbell, The Legal Theory of Ethical Positivism 165 (1996).
  311. . Bagaric, supra note 289, at 166.
  312. . Id.
  313. . Id.
  314. . Scott Wilson, Animals and Ethics, Internet Encyclopedia Phil., [].
  315. . Sentience, Macquarie Dictionary (5th ed. 2009).
  316. . The Shorter Oxford English Dictionary on Historical Principles, supra note 2, at 1942 (3rd ed1973). Examine both the definitions of both “sentient” and “sentience.” Id.
  317. . For a direct discussion of “pathocentric theory” to which this Article references, see H. Verhoog, Defining Positive Welfare and Animal Integrity, in 2 NAHWOA Workshop 108, 113 (Malla Hovi & Roberto García Trujillo eds., 2000).
  318. . Jeremy Bentham, An Introduction to the Principles of Morals and Legislation 311 n. 1 (N.Y., Hafner Pub. Co. 1948) (1789) (emphasis added).
  319. . In a similar vein, pathocentric theory in this context is based on the idea that “animal suffering is prima facie wrong. . . . Sentient animals are the equal [of man] in their ability to feel pain . . . [H]igher animals are given moral status by pathocentrics.” Verhoog, supra note 314. 
  320. . See generally Verhoog, supra note 314 (providing background information and general descriptions of various non-consequentialist theories and their origins).
  321. . W. N. Hohfeld, defined four categories of rights: claim-rights, privileges, powers and immunities. See Wesley Newcomb Hohfeld, Some Fundamental Legal Conceptions as Applied in Judicial Reasoning, in Fundamental Legal Conceptions: As Applied in Judicial Reasoning and Other Legal Essays 22, 36–38 (Walter Wheeler Cook ed., 1920). He qualifies this by implying that only a claim-right accords with the proper meaning of the term. Id.
  322. . John Kleinig, Human Rights, Legal Rights and Social Changein Human Rights 36, 44–45 (Eugene Kamenka & Alice Erh-Soon Tay eds., 1978) (emphasis added).
  323. . Thomas Hobbes, Leviathan or the Matter, Forme and Power of a Commonwealth Ecclesiasticall and Civil 84 (Michael Oakeshott ed., Basil Blackwell 1947) (1651) (emphasis added).
  324. . See Geoffrey Marshall, Rights, Options, and Entitlementsin 2 Oxford Essays in Jurisprudence 228, 241 (A.W.B. Simpson ed., 1973).
  325. . H. J. McCloskey, Rights – Some Conceptual Issues, 54 Australas. J. Phil. 99, 115 (1976).
  326. . Tom D. Campbell, The Legal Theory of Ethical Positivism 164 (1996).
  327. . T. L. S. Sprigge, The Rational Foundations of Ethics 216–17 (1987).
  328. . Marshall, supra note 321, at 241.
  329. . D. J. Galligan, The Right to Silence Reconsidered, 41 Current Legal Probs. 69, 88 (1988).
  330. . Tom Regan, The Case for Animal Rights 243 (1983).
  331. . Id.
  332. . James Rachels, Why Animals Have a Right to Libertyin Animal Rights and Human Obligations 122, 124 (Tom Regan & Peter Singer eds., 2nd ed. 1989).
  333. . Id. at 125.
  334. . H. L. A. Hart, Are There Any Natural Rights?, 64 Phil. Rev. 175, 175 (1955).
  335. . Michael Tooley, Abortion and Infanticidein Applied Ethics 57, 69 (Peter Singer ed., 1986).
  336. . See Peter Carruthers, The Animals Issue: Moral Theory in Practice 170–93 (1992) (using examples in the animal kingdom to explain and support instances of animal consciousness). See generally Smith, supra note 226 (discussing the self-awareness of animals as well as animal mental states through a series of scientific experiments).
  337. . See Tooley, supra note 332, at 66–67.
  338. . For a discussion of confining the application of rights, see generally Hugh LaFollette & Niall Shanks, The Origin of Speciesism, 71 Phil. 41 (1996).
  339. . James Rachels, Created From Animals: The Moral Implications of Darwinism 181 (1990).
  340. . See id. at 185–87 (discussing the similarities between humans and animals and discussing treatment of humans with disabilities in relation to rationality); see also Peter Singer, All Animals are Equal, in Animal Rights and Human Obligations, supra note 329, at 73, 80–81.
  341. . Michael Allen Fox, The Case for Animal Experimentation: An Evolutionary and Ethical Perspective 50 (1986).
  342. . Id. at 57–58.
  343. . See id. at 80.
  344. . Carruthers, supra note 333, at 35.
  345. . See id. at 105, 143.
  346. . See id. at 139, 145.
  347. . Rawls, supra note 296, at 448.
  348. . John Rawls, Outside the Scope of the Theory of Justice, in Political Theory and Animal Rights 154, 156 (Paul A. B. Clarke & Andrew Linzey eds., 1990).
  349. . Id. at 155.
  350. . Id. at 156.
  351. . See Tom Regan, The Case for Animal Rightsin Animal Rights and Human Obligations, supra note 329, at 105, 106. See generally Carruthers, supra note 333, at 35–36 (explaining the prerequisite requirements to establish moral standing under a contractualist approach).
  352. . See Regan, supra note 348, at 106–07. But see Carruthers, supra note 333, at 99, 105 (arguing that, although animals lack moral standing under a contractualism approach, cruelty towards them is nevertheless unjustified due to the potential indirect moral significance animals may have).
  353. . See Regan, supra note 348, at 106–08.
  354. . See Bagaric, supra note 15, at 188.
  355. . See Ferdowsian & Merskin, supra note 240, at 451.
  356. . See McMillan et al., Characteristics of Canine Victimssupra note 14, at 104–05; McMillan, Outcomes for Dogs, supra note 14.
  357. . See generally Duncan Green, How Change Happens 48–49 (2016) (explaining from a historical lens how shifting social norms can characterize notable legal changes as well).
  358. . Deborah N. Archer, Still Fighting After All These Years: Minority Voting Rights 50 Years After the March on Washington, 16 Berkeley J. Afr.-Am. L. & Pol’y 69, 69 (2014).
  359. . Racial Disparity, Sentencing Project (2019),
    issues/racial-disparity/ [] (providing articles that discuss ongoing issue in racial disparity among the incarcerated population).
  360. . Bas Sanders, Global Animal Slaughter Statistics and Charts, Faunalytics (Oct. 10, 2018), [].
  361. . Hensley et al., supra note 10, at 489.
  362. . Frank R. Ascione, Children Who Are Cruel to Animals: A Review of Research and Implications for Developmental Psychology, 6 Anthrozoos 226, 228 (1993).
  363. . See Longobardi & Badenes-Ribera, supra note 181, at 201.
  364. . Ascione, supra note 359; Longobardi & Badenes-Ribera, supra note 181, at 201.
  365. . Id.
  366. . Longobardi & Badenes-Ribera, supra note 181, at 202.
  367. . See van Loon et al., supra note 251, at 641; McMillan et al., Characteristics of Canine Victims, supra note 14, at 104–05.
  368. . Mirko Bagaric et al., Trauma and Sentencing: The Case for Mitigating Penalty for Childhood Physical and Sexual Abuse, 30 Stan. L. & Pol’y Rev. 1, 6 (2019).
  369. . Id.
  370. . Mirko Bagaric & Gabrielle Wolf, Sentencing By Computer: Enhancing Sentencing Transparency and Predictability, and (Possibly) Bridging the Gap Between Sentencing Knowledge and Practice, 25 Geo. Mason L. Rev. 653, 665 (2018).
  371. . Maggie Astor, On This Issue, Both Sides Concede They Were Wrong, N.Y. Times, May 17, 2019, at A18.
  372. . See Bagaric et al., supra note 365, at 19–21.
  373. . See Tex. Penal Code §§ 42.09(a)–(c) (West, Westlaw through 2019 Reg. Sess.); see also id. § 12.34(a) (Westlaw). In tandem, these two laws can work together to create a penalty for certain animal cruelty violations exceeding five years.
  374. . See 18 U.S.C.A. § 48 (Westlaw through Pub. L. No. 116-72).
  375. . See Astor, supra note 368.
  376. . See Bagaric et al., supra note 365, at 43.
  377. . See Danielle Kaeble & Lauren Glaze, Bureau Just. Stat., Correctional Populations in the United States, 2015, at 5–6 (2015).
  378. . See, e.g., 28 U.S.C. § 994(a)(3) (2012); 18 U.S.C. §§ 3563(a), 3583(d) (2018).
  379. . See, e.g., 18 U.S.C. §§ 3563(b), 3583(d) (2018).
  380. . Id. §§ 3563(b)(15)–(18).
  381. . See Erickson v. Ministry for Property Industries [2017] NZCA 271 at [58](a).
  382. . Id. at [1]–[12].
  383. . Id. at [4](a)–(e).
  384. . Id.
  385. . Id. at [1]–[2].
  386. . Id. at [51].
  387. . Id. at [57].
  388. . See van Loon et al., supra note 251, at 641; McMillan et al., Characteristics of Canine Victims, supra note 14, at 104–05.