I think all of us would like to know.

I know about Miletski... I don't know if it can be considered scientific, but it's academic literature.

Well, scientific studies about zoosexuality are rare. I'm not aware of any that explain the mechanics of it, only for sexual fetishism which is much broader and - I have experimented on myself to determine this - not the same thing.

If I had to make an informed guess, I would say that sexual attraction has a genetic basis, that there are some genes which construct some neural pathways that make some shapes, sounds, or smells inherently arousing: species which evolve such a mechanism would waste less time on mating with inanimate objects, different species, or the same genders, or people outside reproductive age, or the wrong orifice.

Humans do all of those things of course, but if it's genetic, it can be rare, and we can be that rarity.

The short answer to your questions is "we don't know". We don't know why some people are zoophiles. We don't know the factors that lead to it. There is very little to no research on the subject.

I'd like that research to get done too, but as it stands, we're out of luck

I don't know why, scientifically, some people feel a greater attraction toward nonhuman animals than toward human beings. I have my own ideas on it, but they pretty much only apply to me psychologically and can't properly be used to explain this phenomenon in general.

When I interact with people socially, there tend to be certain social expectations and roles, with certain actions accompanying each. They might be in a classroom, a theater, or someone's house party. My interactions in these circles tend to be mostly verbal and/or rational. Lots of joking and debate, but not a whole lot of physical contact.

With animals, those options aren't available, and communication has to be done through body language and touch. Also, much of the interaction focuses on concrete objects (toys, brushes, etc.) rather than abstract ideas.

The thing is, in my mind, the transition from ordinary interaction to sexual interaction with willing partners is easier and more natural with animals than with people. My mental model of a person focuses on their opinions or mental state, while my mental model of an animal can focus more on the physical and emotional aspects.

Even though I know millions of couples do this every day, I just don't understand the transition from high-level cognitive function (for instance, discussion of Shakespeare's Macbeth) to the raw instincts involved in sex. As such, animals interest me more because when I'm with them I can, to an extent, turn off those higher cognitive functions getting in the way of any attraction under the surface.

TL;DR: Animals are simpler, so I can focus on their bodies, while people are more complicated to understand.

I refuse to take genetics as an explanation to interspecies attraction. Basically, a baby is born as a pansexual; which "switches" are flicked onto the "on" position depends largely on environmental and social factors. One factor I think plays a leading role is general body features. Josef Maassen said in his book "Zoophilie - Die sexuelle Liebe zu Tieren" that those features that usually are deemed "erotic" in humans are also those that usually turn animals into an erotic target. "The godly hips of a mare", as he put it, is directly linked to the usual genetic imprint of connecting broad hips in females with enhanced fertility, for examle. Other features like fur match the "cuddliness" factor and thus mainly furred animals are what captures the interest of the average zoo. That´s why dog and horse zoos largely outnumber people with other species preferrences like pigs, for example. The closer to human erotic triggers, the more likely a species becomes a "target" for zoos. The "cuddle" factor, accessibility/availability, safety issues etc...all of that plays a major role. Another big factor is the symbolism that´s connected to the species of interest. Horses usually are considered to be "masculine" because of their muscular appearance. Muscularity = male,virility, power, that´s what most people seem to subconsciously think. I can´t count the incidents where I met strangers while walking with my mare and they always asked if "he is a nice horse, can I pet him".

Many zoos seem to be attracted to the human qualities they connotate with a certain species. The proverbial unlimited trust of dogs, the "freedom" they connotate with horses although most horses aren´t free at all. There are individuals who are attracted to a certain species as a part of role playing. Some others seem to be attracted to animals because they yearn for "animalistic, unrestrained sexuality". Others are into it because of the taboo ; breaking this taboo is what really gives them the kicks they need.

Summary: There is no single cause that turns you into a zoo. There is no explanation so far and I heavily doubt there ever will be one that can be applied to each and every zoophile. I doubt that genetics are a major factor and tend to think that some answers to that question are hidden in the human subconsciousness; everyone of us is responsible to plunge into it to find out whether his attraction to animals is valid and really focused on the animal itself or just a symptom of other personal issues buried deep in your own subconscious.

Shyness towards humans can turn you towards animals as emotional and sexual partners, for example. Animals usually are seen as a more safe and non judgemental way to explore sexuality by people falling under this category. Others feel rejected by humans and thus turn towards animals; I personally think that this isn´t "proper zoophilia", but some form of substitution.

Over the years I´m into this now, I heard so many "reasons" why someone is zoo: "animals don´t lie to you", " they don´t judge you" , " sex with them is uncomplicated", "I don´t have to talk to them or buy expensive stuff" , " their trust is unconditional" , " sex with them is so much wilder and more exciting" etc...but every single "reason" can easily be debunked; so I´ve decided to quit searching for an answer a long time ago. I do not have issues with humans in general, with women specifically, I do not need to do role playing as a "well endowed, fiercely copulation stallion" out of personal insecurity about my dick size, I´m not in it for "animlistic, wild and unrestrained sex"....I simply don´t know why I am a zoophile. I know that I´m not because of all the made up "reasons" I wrote above and that is all I need to know. All the horses I have to deal with seem to tell me that I´m one of them...and that´s more than enough "reason" for me.

I_Want_ToKnow, it is known that our genes program us to act altruisticly or loving towards our kin and mates so to ensure the survival of copies of themselves. Those genes that tell you to act a certain way towards kin and mates have instead lead to you forming an attachement to a different species instead. Psychologicaly you have made a bit of an unintended mixup, contrary to the survival of your genes. They would like you to mate with other humans but in theory the desire to mate cannot be too specific because that could hinder reproduction. For that and other reasons it's not difficult to see how zoophilic attractions can form. That is my guess anyway.

There is also the fact that animals unlike humans cannot consent to or explicitly refuse a sexual act. This makes them an easy outlet for people wanting easy sexual gratification and thus sometimes sexual bonding behaviors

There are many reasons to be zoophile than there are zoophiles.

Each zoophiles has its own reasons.

Assuming you’re still alive afterwards, after you've been kicked that far!

I don’t think it’s a case of being able to take advantage of animals that causes people to indulge in sexual activity with them; rather, it’s simply that they’re not going to be judgmental about it. From their behaviour, it can be taken that animals other than humans regard sex as just another function, like eating, sleeping, going to the lavatory etc. So, they’re not going to call you a pervert or refuse to speak to you ever again if you ‘try it on’ with them. If they don’t want to go along with you, they’ll simply walk away.

It’s acknowledged that people frequently use their pets in place of social interaction with other humans. Humans are rather tricky, complex creatures to get along with, and if you’ve problems interacting with them socially, then other animals offer an easier way to go. And, social interactions with non-human animals are considered perfectly OK – if a little eccentric – by most people; it’s only when it comes to sex that anybody has any problems.