||This article may contain original research. (November 2007)|
Zoosadism is a term coined by Ernest Borneman referring to pleasure (sometimes sexual pleasure) derived from cruelty to animals. Zoosadism is part of the Macdonald triad, a set of three behaviors that are a precursor to sociopathic behavior.
Schedel-Stupperich (2001) state that some horse-ripping incidences have a sexual connection, and in general, the link between sadistic sexual acts with animals and sadistic practices with humans or lust murders has been heavily researched. Some murderers tortured animals in their childhood, with some of them also practicing bestiality. Ressler et al. (1988) found that 36% of sexual murderers described themselves as having abused animals during childhood, with 46% of them reporting that they had abused animals during adolescence, and (1986) that eight of their sample of thirty-six sexual murderers showed an interest in zoosexual acts.
In 1971, American researchers profiled the typical animal harmer as being a nine-and-a-half-year-old boy, with an I.Q. of 91 and a history of gross parental abuse. The UK "Young Abusers Project" sees children as young as five who have a record of sexual offences or "extremely" violent behavior. Of such people, child psychiatrist Dr Eileen Vizard, commented:
"They stomp on small hamsters or mice. Squeeze them or burst them, set fire to their fur. Gratuitous cruelty for which there can be no justification."
Dr Vizard commented:
"…cruelty to animals, if accompanied by a sexual interest in animals, is a high-risk indicator of a future sex offender."
Studies have shown that individuals who enjoy or are willing to inflict harm on animals are more likely to do so to humans. One of the known warning signs of certain psychopathologies, including antisocial personality disorder, is a history of torturing pets and small animals. According to the New York Times:
"the FBI has found that a history of cruelty to animals is one of the traits that regularly appear in its computer records of serial rapists and murderers, and the standard diagnostic and treatment manual for psychiatric and emotional disorders lists cruelty to animals as a diagnostic criterion for conduct disorders."
Alan R. Felthous reported in his paper "Aggression Against Cats, Dogs, and People" (1980) that
"A survey of psychiatric patients who had repeatedly tortured dogs and cats found all of them had high levels of aggression toward people as well, including one patient who had murdered a boy."
This is a commonly reproduced finding, and for this reason, violence (including sexually oriented violence) toward animals is considered a serious warning sign of potential serious violence towards humans.
Over the past fifty years, modern research has confirmed that not all sexual activity with animals is violent nor dangerous. This preconception has been criticized by researchers, for the bias that can result within bona fide research into zoosadism and abuse. Older research often focused on known abusers such as violent juvenile offenders, and generalizations from such studies have often been criticized post-publication as being tainted by circular reasoning, arguments from incredulity, and other fallacies:
"There are different people who engage in sex with animals and not the kind of interaction but first and foremost the quality of the relationship seems to distinguish between them. This emotional relation or at least the respect they show towards the will of the involved animal should be more closely investigated, when conducting research that includes bestiality. Because [it is] this, the quality of the interaction and the relationship – that may be loving, neutral, or violent – and not the fact of a sexual interaction [which] is important, and provides information for a better understanding of bestiality and zoophilia and their significance in relation to other phenomena."—Andrea Beetz, 
Kidd and Kidd (1987) identified that
"most of these older research and models rarely took the variety of possible interactions and relations into account, studying the physical acts in isolation."
Andrea Beetz comments that, perhaps because of this,
"In most [popular] references to bestiality, violence towards the animal is automatically implied. That sexual approaches to animals may not need force or violence but rather, sensitivity, or knowledge of animal behavior, is rarely taken into consideration."
In the same manner, Dr. Stephanie Lafarge, an assistant professor of Clinical Psychiatry at the New Jersey Medical School and sex therapist, who is the Director of Counseling at the American Society for the Prevention of Cruelty to Animals and works with the New York correctional system, is quoted in a 1999 newspaper article as saying that "It's important to make the distinction [between animal sexual abuse and zoophilia]" and that
"There is no evidence yet that zoophilia leads to sexual deviation, but that's not to say that's not the case. We do make the link between other forms of physical violence against animals as being a predicator of physical violence against women and children. I would go on to say that someone who is sexually violent with an animal ... is a predator and might very well do that toward people." 
"No one can argue about the objective harm resulting from a behavior like rape. Such harm arises from the absence of consent and the trauma that accompanies and follows from the act ... Our research suggests that forcing sex on an unwilling animal is rare among adult zoophiles ... The question of consent is usually conflated with the question of harm, which we believe to be the better question. Zoophiles appear to be extremely caring and concerned for their animal(s) and people who know them would be hard put to claim abuse. Implicit in [the bill] is that sex with an animal in itself constitutes abuse."
Beetz states categorically:
"Former, as well as the here presented research, suggests that zoophilia itself does not represent a clinically significant problem and is not necessarily combined with other clinically significant problems and disorders, even if it may be difficult for some professionals to accept this."
Legal status 
In the United States, since 2010, it has been a federal offense to create or distribute "obscene" depictions of "living non-human mammals, birds, reptiles, or amphibians ... subjected to serious bodily injury". This statute replaced an overly broad 1999 statute which was found unconstitutional in United States v. Stevens.
Zoosadism towards insects is also exhibited by some. The classic example of this subvariety of "schoolyard viciousness" is the child who pulls off a fly's wings. The Roman writer Plutarch, in his Parallel Lives, claims that the Emperor Domitian amused himself by catching flies and impaling them with needles.
Notable zoosadists 
- Dennis Rader
- Jun Matsubara
- Kenny Glenn
- Jim Jones
- Henry Lee Lucas
- Otis Toole
- Rostislav Bogoslevsky
- John Duffy and David Mulcahy
- Richard Chase
See also 
- J. M. MacDonald (1963). "The Threat to Kill". American Journal of Psychiatry 120 (2): 125–130.
- "The chain of cruelty". BBC News. 9 May 2000.
- Goleman, Daniel (7 August 1991). "Child's Love of Cruelty May Hint at the Future Killer". New York Times
- Felthous, Alan R. (1980). "Aggression Against Cats, Dogs, and People". Child Psychiatry and Human Development (10): 169–177
- Beetz, Andrea (2002). Love, Violence, and Sexuality in Relationships between Humans and Animals. Shaker Verlag GmbH. ISBN 3-8322-0020-7.
- Kidd, A.H.; Kidd, R.M. (1987). "Seeking a theory of the human/companion animal bond". Anthrozoos (1): 140–157
- Roth, Melinda (15 December 1999). ALL OPPOSED, SAY "NEIGH". Riverfront Times
- Robson, Ruthann (2010-12-14) Animal Porn - Criminalized by Federal Law Again, Constitutional Law Prof Blog
- US Code TITLE 18 > PART I > CHAPTER 3 > § 48
- Police arrest suspected serial killer | Jerusalem Post
- Cowan, Rosie (11 August 2005). "Childhood cruelty to animals may signal violence in future". The Guardian (London). Retrieved 20 April 2010.
- CrimeLibrary.com/Serial Killers/Truly Weird & Shocking/Richard Trenton Chase: The Vampire of Sacramento