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Animal passions: Why would anyone want to have sex with an animal?

Note: A shortened version of this article was first published in The Independent.

Last month, Denmark passed a law making bestiality a criminal offence from July 1st in a move to tackle animal-sex tourism. Bestiality (also known as zoophilia) is typically defined as relating to recurrent intense sexual fantasies, urges, and sexual activities with non-human animals. At present, there are still a number of countries where zoophilia is legal including Brazil, Mexico, Thailand, Finland, Hungary, and Romania. In the US there is no federal law against zoophilia although most states class it as a felony and/or misdemeanour although in some states it is technically legal (for example, Texas, Kentucky, Nevada, New Jersey, New Hampshire, Wyoming, West Virginia, and New Mexico).

Over the last few years I have written articles on the psychology of many different types of zoophilia including those who have engaged in sexual activities with dogs (cynophilia), cats (aelurophilia), horses (equinophilia), pigs (porcinophilia), birds (ornithophilia), dolphins (delphinophilia), lizards (herpetophilia), worms (vermiphilia), and insects (formicophilia). Dr. Alfred Kinsey shocked the US back in the 1950s when his infamous ‘Kinsey Reports’ claimed that 8% of males and 4% females had at least one sexual experience with an animal. Perhaps unsurprisingly, there was a much higher prevalence for zoophilic acts among people that who worked on farms (for instance, 17% males had experienced an orgasmic episode involving animals). According to Kinsey, the most frequent sexual acts that humans engaged in with animals comprised calves, sheep, donkeys, large fowl (ducks, geese), dogs and cats.

In the 1970s, world renowned sexologist Professor John Money claimed that zoophilic behaviours were usually transitory occurring when there is no other sexual outlet available. However, research carried out in the 2000s shows this not be the case. Up until the advent of the internet, almost every scientific or clinical study reported on zoophilia were case reports of individuals that has sought treatment for their unusual sexual preference. However, the internet brought many like-minded people together and there are dozens of websites where zoophiles chat to each other online and share their videos including the Beast Forum, the largest online zoophile community in the world with tens of thousands of members.

Almost all of the recently published studies have collected their data online from non-clinical samples. All of these studies report that the overwhelming majority of self-identified male and female zoophiles do not have sex with animals because there is no other sexual outlet but do so because it is their sexual preference. The most common reasons for engaging in zoophilic relationships were attraction to animals out of either a desire for affection, and a sexual attraction toward and/or a love for animals.

For instance, a study by Dr. Hani Miletski surveyed 93 zoophiles (82 males and 11 females). Only 12% of her sample said they engaged in sex with animals because there were no human partners available, and only 7% said it was because they were too shy to have sex with humans. For the females, the main reasons for having sex with animals was because they were sexually attracted to the animal (100%), had love and affection for the animal (67%) and/or because they said the animal wanted sex with them (67%). Most of Miletski’s sample preferred sex with dogs (87% males; 100% females) and/or horses (81% males; 73% females). Only 8% of males wanted to stop having sex with animals and none of the females. Unlike case study reports of zoophilia published prior to 2000, the studies published over the last 15 years using non-clinical samples report the vast majority of zoophiles do not appear to be suffering any significant clinical significant distress or impairment as a consequence of their behaviour.

In 2011, Dr Anil Aggrawal published a comprehensive typology of zoophilia in the Journal of Forensic and Legal Medicine. Dr. Aggrawal’s claimed there were ten different types of zoophile based on both the scientific and clinical literature, as well as some theoretical speculation. For instance:

  • Humananimal role-players – those who never have sex with animals but become sexually aroused through wanting to have sex with humans who pretend to be animals.
  • Romantic zoophiles – those who keeps animals as pets as a way to get psychosexually stimulated without actually having any kind of sexual contact with them.
  • Zoophilic fantasizers – those who fantasize about having sexual intercourse with animals but never actually do.
  • Tactile zoophiles – those who get sexual excitement from touching, stroking or fondling animals or their genitals but do not actually have sexual intercourse with animals.
  • Fetishistic zoophiles – those who keep various animal parts (especially fur) that are used as erotic stimuli as a crucial part of their sexual activity (typically masturbation). (See my previous blog on the use of an animal part as a masturbatory aid)
  • Sadistic bestials – those who derive sexual arousal from the torturing of animals (known as zoosadism but does not involve sexual intercourse with the animal.
  • Opportunistic zoosexuals – those who have normal sexual encounters but would have sexual intercourse with animals if the opportunity arose.
  • Regular zoosexuals – those who prefer sex with animals than sex with humans (but are capable of having sex with both). Such zoophiles will engage in a wide range of sexual activities with animals and love animals on an emotional level.
  • Homicidal bestials – those who need to kill animals in order to have sex with them. Although capable of having sex with living animals, there is an insatiable desire to have sex with dead animals.
  • Exclusive zoosexuals – those who only have sex with animals to the exclusion of human sexual partners.

Personally, I don’t view human-animal role players as zoophiles as this would include those in the Furry Fandom (individuals that dress up and interact socially as animals). There is no official definition of what a ‘furry’ actually is although most furries would agree that they share an interest in fictional anthromorphic animal characters that have human characteristics and personalities and/or mythological or imaginary creatures that possess human and/or superhuman capabilities. The furry fandom has also developed its own vocabulary including words such as ‘fursona’ (furry persona), ‘plushie’ (person who has sex with cuddly toys), and ‘yiff’ (furry pornography). A study by David J. Rust of 360 members of the furry community suggested less than 1% were plushophiles and that 2% were zoophiles.

Many zoophiles believe that in years to come, their sexual preference will be seen as no different to being gay or straight. This is not a view I adhere to especially because animals cannot give consent (although many zoophiles claim the animals they have sexual relationships with do give ‘consent’). The one thing we do know is that the internet has revolutionised the way we carry out our research and get access to ‘hard to reach’ groups. Thanks to online research, zoophilia is just one of many sexually atypical behaviours that we now know more about both behaviourally and psychologically.

Dr. Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Aggrawal, A. (2011). A new classification of zoophilia. Journal of Forensic and Legal Medicine, 18, 73-78.

Beetz, Andrea (2002). Love, Violence, and Sexuality in Relationships between Humans and Animals. Germany: Shaker Verlag.

Kinsey, A. C., Pomeroy, W. B., Martin, C.E., Gebhard, P.H. (1953). Sexual Behavior in the Human Female. Philadelphia, PA: W.B. Saunders Company.

Kinsey, A. C., Pomeroy, W. B., Martin, C.E., (1948). Sexual Behavior in the Human Male. Philadelphia, PA: W.B. Saunders Company.

R.J. Maratea (2011). Screwing the pooch: Legitimizing accounts in a zoophilia on-line community. Deviant Behavior, 32, 918-943.

Miletski, H. (2000). Bestiality and zoophilia: An exploratory study. Scandinavian Journal of Sexology, 3, 149–150.

Miletski, H. (2001). Zoophilia – implications for therapy. Journal of Sex Education and Therapy, 26, 85–89.

Miletski, H. (2002). Understanding bestiality and zoophilia. Germantown, MD: Ima Tek Inc.

Williams, C. J., & Weinberg, M. S. (2003). Zoophilia in men: A study of sexual interest in animals. Archives of Sexual Behavior, 32, 523–535.

Blog-nitive psychology: 500 articles and counting

It’s hard for me to believe that this is the 500th article that I have published on my personal blog. It’s also the shortest. I apologise that it is not about any particular topic but a brief look back at what my readers access when they come across my site. (Regular readers might recall I did the same thing back in October 2012 in an article I wrote called ‘Google surf: What does the search for sex online say about someone?’). As of August 26 (2014), my blog had 1,788,932 visitors and is something I am very proud of (as I am now averaging around 3,500 visitors a day). As I write this blog, my most looked at page is my blog’s home page (256,262 visitors) but as that changes every few days this doesn’t really tell me anything about people like to access on my site.

Below is a list of all the blogs that I have written that have had over 10,000 visitors (and just happens to be 25 articles exactly).

The first thing that struck me about my most read about articles is that they all concern sexual fetishes and paraphilias (in fact the top 30 all concern sexual fetishes and paraphilias – the 31st most read article is one on coprophagia [7,250 views] with my article on excessive nose picking being the 33rd most read [6,745 views]). This obviously reflects either (a) what people want to read about, and/or (b) reflect issues that people have in their own lives.

I’ve had at least five emails from readers who have written me saying (words to the effect of) “Why can’t you write what you are supposed to write about (i.e., gambling)?” to which I reply that although I am a Professor of Gambling Studies, I widely research in other areas of addictive behaviour. I simply write about the extremes of human behaviour and things that I find of interest. (In fact, only one article on gambling that I have written is in the top 100 most read articles and that was on gambling personality [3,050 views]). If other people find them of interest, that’s even better. However, I am sometimes guided by my readers, and a small but significant minority of the blogs I have written have actually been suggested by emails I have received (my blogs on extreme couponing, IVF addiction, loom bandsornithophilia, condom snorting, and haircut fetishes come to mind).

Given this is my 500th article in my personal blog, it won’t come as any surprise to know that I take my blogging seriously (in fact I have written academic articles on the benefits of blogging and using blogs to collect research data [see ‘Further reading’ below] and also written an article on ‘addictive blogging’!). Additionally (if you didn’t already know), I also have a regular blog column on the Psychology Today website (‘In Excess’), as well as regular blogging for The Independent newspaper, The Conversation, GamaSutra, and If there was a 12-step ‘Blogaholics Anonymous’ I might even be the first member.

“My name is Mark and I am a compulsive blogger”

Dr. Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Griffiths, M.D. (2012). Blog eat blog: Can blogging be addictive? April 23. Located at:

Griffiths, M.D. (2012). Stats entertainment: A review of my 2012 blogs. December 31. Located at:

Griffiths, M.D. (2013). How writing blogs can help your academic career. Psy-PAG Quarterly, 87, 39-40.

Griffiths, M.D. (2013). Stats entertainment (Part 2): A 2013 review of my personal blog. December 31. Located at:

Griffiths, M.D. (2014). Top tips on…Writing blogs. Psy-PAG Quarterly, 90, 13-14.

Griffiths, M.D. (2014). Blogging the limelight: A personal account of the benefit of excessive blogging. May 8. Located at:

Griffiths, M.D., Lewis, A., Ortiz de Gortari, A.B. & Kuss, D.J. (2014). Online forums and blogs: A new and innovative methodology for data collection. Studia Psychologica, in press.

See you later alligator: A beginner’s guide to herpetophilia

In previous blogs I have examined various sub-types of zoophilia including ornithophilia (sexual attraction to birds) and formicophilia (sexual attraction to insects). It wasn’t until very recently, that I came across an article on herpetophilia that according to the online Urban Dictionary is “the sexual attraction to reptiles, commonly dinosaurs or anthropomorphic lizards”. There is a fairly active online community of herpetophiles including (with lots of discussion topics such as “How to please a reptile”). The dinosaur-loving herpetophiles can be found interacting with each other on sites like Lava Dome Five where there is an overt crossover between herpetophilia and macrophilia (i.e., sexual arousal from giants – in this case giant lizards in the form of dinosaurs).

One 2012 online essay I read on the Vivid Random Existence (VRE) website claimed that there was a new emergent form of zoosexuality – human sexual attraction towards lizards (and in particular, monitor lizards) – a subcategory of herpetophilia. It was claimed by VRE that the “lizards of choice” for herpetophilic zoophiles were either the Varanus Salvator (a water monitor lizard) and the Nile Monitor. So you can get an idea of the person putting forward these views, the unnamed VRE author is a 20-year old man who describes himself as the following:

“I am bisexual and zoosexual – I am sexually attracted to multiple genders and multiple species (in other words, I am sexually attracted to male humans, female humans, male non-human animals and female non-human animals). When it comes to sexual attraction, the creature’s gender and species are irrelevant to me. However, I am only attracted to a few species (maybe about 7 or 8)”.

The VRE essay then goes on to talk about the sexual ethics of lizard relationships. VRE claims that lizards do not pair bond in the way that many mammals do and asks the very specific question:

“Is it ethical for a human to have sex with a monitor lizard, even if that lizard only ‘tolerates’ the sex and neither enjoys nor dislikes it? From a utilitarian perspective (a perspective adopted by philosophers such as Peter Singer), there is nothing wrong with having sex with a monitor lizard, so long as no harm occurs…With large animals like horses, such human-horse sexual interactions are clearly acceptable under this philosophy – for example, even if a horse has a neutral opinion regarding sexual encounter with a human, the fact that the horse is larger than the human automatically means that physical ‘abuse’ is less likely to occur to the horse”.

The VRE website also claimed in a previous 2010 online essay (Zoosexuality: Should it be considered acceptable?) that the smaller the animal is, the less ethical the activity becomes. VRE then goes on to say that Nile monitor lizards and Komodo dragons are big enough to accommodate human genitalia but that humans having sex with smaller lizards would be unethical due to anatomical incompatibility. A 2011 VRE essay also claims that there are a sub-group of zoophiles that are sexually attracted to alligators and crocodiles, and that some owners of pet alligators or crocodiles have active sexual relationships with them. The “proof” of this claim was based on a video circulating among online zoophile forums (but I’ve not seen it myself). VRE describes the film’s contents:

“The human in the video is male, and the alligator in the video is also male. The human male is seen anally penetrating the male alligator, who is flipped upside down; the fact that the gator has an erection (and the fact that the gator is not tearing the man to pieces) suggests that the alligator is tolerant of (or possibly even enjoys) the sexual relationship with the human”

The issue of whether it is ethically wrong to have sex with a crocodile is again raised (along with the issue of how dangerous the activity is to start with. In the 2012 essay, VRE then says:

“Many have claimed that zoosexuality is wrong on the grounds that it is physically abusive. Although sex with animals can be abusive depending on the size of the animal, it can also not involve any abuse. In other words, it all depends on the size of the animal, and whether or not it is compatible with a human…When considering other species, it is important to realize that some species are too small for humans to engage in sex with”.

The article also quotes from philosopher Peter Singer’s online essay Heavy Petting (published on the website) in which Singer (Princeton University, US) reviews Midas Dekkers’ Dearest Pet. Singer wrote that:

“Some men use hens as a sexual object, inserting their penis into the cloaca, an all-purpose channel for wastes and for the passage of the egg. This is usually fatal to the hen, and in some cases she will be deliberately decapitated just before ejaculation in order to intensify the convulsions of its sphincter. This is cruelty, clear and simple…But sex with animals does not always involve cruelty. Who has not been at a social occasion disrupted by the household dog gripping the legs of a visitor and vigorously rubbing its penis against them? The host usually discourages such activities, but in private not everyone objects to being used by her or his dog in this way, and occasionally mutually satisfying activities may develop”

I can’t say I agree with any of these arguments, as my own view is that sex should always be consensual and inter-species sexual activity is always non-consensual. Being “cruelty-free” does not make sexual activity with animals an acceptable activity. Singer’s arguments suggest that some animals (e.g., dogs) can engage in cruelty-free sex with humans and that no party is harmed. I can think of (admittedly extreme) scenarios where sex between humans could take place where neither party is harmed but it doesn’t mean it is morally acceptable. For instance, a human who has sex with a deceased person (i.e., a necrophile) technically does no harm to either party but that doesn’t make it acceptable. There is also the scenario that appeared in Quentin Tarantino’s Kill Bill where men had sex with Uma Thurman’s character while she was in a coma. Again, this might be perceived by some as “cruelty-free”, but the common denominator in both these extreme situations is that the sex was non-consensual.

Another related paraphilia to herpetophilia, and sub-category of zoophilia, is that of ophidiophilia that is defined in Dr. Anil Aggrawal’s Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices as a sexual attraction to snakes). There are some really quite bizarre snake sexuality websites including those where there is a crossover with vorarephilia (i.e.. sexual arousal from the idea of being eaten, eating another person, or observing this process for sexual gratification). This seems a logical crossover given that snakes swallow their prey whole (check out the Snake Eats website if you don’t believe me).

An act often associated with ophidiophilia is ophidicism. This is where women voluntarily insert snakes (and sometimes eels) tail first into their vagina to get sexual pleasure as it wriggles free. There are also stories of both men and women allegedly receiving sexual pleasure from snakes wriggling free following anal insertion. Acts of ophidicism have been documented going back to Ancient Greek times. Dr. Brenda Love in her Encyclopedia of Unusual Sex Practices also says the practice was prevalent in Roman times except the women put snakes into their vaginas head first. There are more recent references to the activity in the psychological literature including a case study reported in a 1964 issue of the International Journal of Psychoanalysis by Austrian psychoanalyst Dr. Melitta Sperling.

VRE claims that in the case of animals like snakes, only certain sexual acts with them would be considered abusive. VRE asserts that ophidicism is unethical, and that penile penetration of snakes that are physically incompatible with humans (in terms of size) is animal abuse. However, there are some acts that VRE believes could still be ethical involving snakes (e.g., oral sex – although it wasn’t clear whether that was a human performing oral sex on a snake, vice-versa, or either).

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Aggrawal A. (2009). Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices. Boca Raton: CRC Press.

Aggrawal, A. (2011). A new classification of zoophilia. Journal of Forensic and Legal Medicine, 18, 73-78.

Love, B. (2001). Encyclopedia of Unusual Sex Practices. London: Greenwich Editions.

Singer, P. (2001). Heavy petting. Located at:—-.htm

Sperling, M. (1964). A case of ophidiophilia: A clinical contribution to snake symbolism. International Journal of Psychoanalysis, 45, 227-233.

Vivid Random Existence (2010). Zoosexuality: Should it be considered acceptable? July 20. Located at:

Vivid Random Existence (2011). Crocodilian zoosexuality (or zoophilia): The sexual attraction to alligators and crocodiles. December 5. Located at:

Vivid Random Existence (2012). Lizard zoosexuality (or zoophilia): The sexual attraction to lizards. January 13. Located at:

Fowl play: A brief overview of avian bestiality

I don’t normally write blogs on request, but one of my friends and colleagues here in my department, Dr. Belinda Winder, asked me if I knew anything about sexual paraphilias involving birds. Dr. Winder – no stranger to sexual paraphilias as they feature quite a lot in a new book she’s just co-edited [A Psychologist’s Casebook of Crime: From Arson to Voyeurism] – did pique (or should that be ‘beak’) my interest into the topic so I thought I would have a quick look at what has been done academically.

As it turned out, not a lot but enough to write a blog. In his 2009 book Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices, Dr Anil Aggrawal (Maulana Azad Medical College, New Delhi, India) noted that bestial acts involving birds are commonplace in mythology and folklore. For instance, the Greek god Zeus was said to assume the shape of various animals as part of his seduction technique. He transformed into a swan to order to seduce Leda (the mother of Troy), and became an eagle to carry off a young Ganymede. In a separate part of his book, Aggrawal writes about Rome where the practice of bestiality was also commonplace. Examples cited by Aggrawal include bestial acts with chickens. He also noted that professional people supplied animals specifically for bestial purposes. For instance, the Belluari supplied dogs and monkeys, the Caprarii supplied female goats, and the Anserarii supplied geese.

An online essay by Cameron King noted that in the 13th century, the bestiality laws were different between having sex with a mammal and with a chicken. Avian sex was seen as a much less serious offence because fowl were less costly to replace than farm animals. However, King did add that “eating the bird after making love to it was frowned upon and could land you with two or three years of fasting”.

The Marquis de Sade (whose name of course gave rise to sexual sadism) wrote about avian sex in a Parisian brothel where they employed a turkey. de Sade claimed: “The girl holds the bird’s neck locked between her thighs, you have her ass straight ahead of you for prospect, and she cuts the bird’s throat the same moment you discharge”.

Academically, Richard von Krafft-Ebing was arguably the first person to write about bestial acts with birds in his 1886 book Psychopathia Sexualis. In a chapter on zoosadism, Krafft-Ebing wrote of a male poet who “became powerfully excited sexually whenever he saw cows slaughtered” and another male who “committed sodomy with geese, and cut their necks off, tempore ejaculationis!” This latter practice is called avisodomy and is listed as one of the many acts of zoophilia in Dr. Aggrawal’s new classification typology in a 2011 issue of the Journal of Forensic and Legal Medicine. The practice typically involves breaking the neck of a bird and then penetrating it. In the 2001 book Sexual Relations of Mankind, Mantegazza claimed that: the Chinese are famous for their love affairs with geese. Just when they are at the point of ejaculation they wring off the birds’ necks in order that they may get the pleasure of the last spasms of the anal sphincters of the dying geese”.

A similar account of avisodomy is also described in The Encyclopedia of Unusual Sex Practices by Dr. Brenda Love. Here it is referred to as the “the ancient practice of having sex with a bird. As the man is about to orgasm he breaks the neck of the bird, causing the bird’s cloaca sphincter to constrict and spasm, thus creating pleasurable sensations for the man”. (In zoological anatomy, a cloaca is the posterior orifice that serves as the only opening for the urinary, intestinal and reproductive activities in some animal species). Zoosadistic sexual elements involving birds have been reported in case studies of high profile serial killers – the most notorious being Jeffrey Dahmer (that I briefly covered in a previous blog).

In Dr. Alfred Kinsey’s groundbreaking studies on human sexual behaviour in the late 1940s and early 1950s, he reported that 8% of the males and almost 4% of the females had experienced a bestial act with animals at some point in their lives. The frequency of such behaviour among males was highest for those raised on farms (with 17% of these men reported experiencing orgasm as a result of animal contact). Although the animals most frequently involved were calves, sheep, donkeys, dogs, and cats, a significant minority of bestial acts involved large fowl (i.e., ducks and geese). Such acts are not unknown in contemporary societies and include the recent case reported in the Daily Mirror of a 23-year old man who hanged himself after his wife came home and found him having sex with a chicken.

One of the most infamous accounts of bestial activity was reported by porn publisher Larry Flynt in his autobiography (An Unseemly Man). Flynt claimed that he had sex with a chicken before his tenth birthday. He was told by older boys that having sex with a chicken was as good as having sex with a girl. He wrote:

“I caught one of my grandmother’s hens out behind the barn, managed to insert my penis into its egg-bag, and thrust away. When I let the chicken go it started towards the main house, staggering, squawking and bleeding. Fearing that my grandmother would see what had happened, I caught it, wrung its neck and threw it in the creek”.

Ornithophilia is a sub-class of zoophilia and specifically refers to those individuals who are sexually aroused by the thought and/or the act of having sex with birds. As far as I have been able to establish, there are no specific case studies in the literature that refer to the condition, and the only specific mention of ‘ornithophilia’ I have come across in the academic literature it is in the writings of Aggrawal (including his most recent 2011 paper mentioned earlier). Other others such as Helen Munro (writing in a 2006 editorial of The Veterinary Journal) have noted that sexual contact with birds exists, but none of these provide any kind of validated case study.

However, I did come across a recent case reported in the journal Romanian Neurosurgery that described the late onset of zoophilia in a 42-year old man who suddenly started engaging in zoophilic behaviour following an aneurysm in the posterior cerebral artery. More specifically, he developed a sexual interest towards the hens in his garden, and his wife found him several times having sex with the hens. Unfortunately, the man died a few weeks later following a rupture of the aneurysm.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Aggrawal A. (2009). Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices. Boca Raton: CRC Press.

Aggrawal, A. (2011). A new classification of zoophilia. Journal of Forensic and Legal Medicine, 18, 73-78.

Ene, S., A. Sasaran, A. (2011). Zoophilic behavior in a patient with posterior cerebral arterial aneurysm. Romanian Neurosurgery, 18, 349-355.

King, C. (2010). The A to Z of sexual history: A – Avisodomy: The act of a human engaging in sexual activity involving a bird. Located at:

Krafft-Ebing, R. von (1886). Psychopathia Sexualis. Philadelphia, PA: F.A. Davis.

Love, B. (2001). Encyclopedia of Unusual Sex Practices. London: Greenwich Editions.

Mantegazza, P. (2001). The Sexual Relations of Mankind. Honolulu, Hawaii: University Press of the Pacific.

Munro, H.M.C. (2006). Animal sexual abuse: A veterinary taboo? The Veterinary Journal, 172, 195-197.

Shaffer, L. & Penn J. (2006). A comprehensive paraphilia classification system. In E.W. Hickey (Ed.), Sex Crimes and Paraphilia (pp.69-93). Pearson, Prentice Hall, New Jersey.