Animals are pretty unsanitary compared to humans and you're more likely to catch then transmit a disease from close physical contact (not necessarily sex) with one than with a human, especially if it's wild animal.

I think some people consider animals unclean. They roll around in mud, they poop in their stall, they never take showers. Also many people consider animals as beneath humans in the sense that humans are meant to dominate them by raising them for meat, milk and their skins, not something to have sex with.

Society is what makes people think that it's gross or repulsive. From my understanding, people are to stubborn and or afraid to be singled out as zoosexual sympathizers.

Two words describe the source of both this prejudice and virtually every other one: I'M SPECIAL!!!!

Specifically, people see in animals all of the baser parts of human existence: eating, shitting, fighting, sex. Raw brutality and terror. When people think of humans (and by extension themselves) they usually think of something greater: of pyramids, literature, space shuttles, and calculus. Emotions are kind of mixed, but basically, the greater positive ones, like love, are supposed to be uniquely human because they are undeniable positive experiences and can be described beautifully in language and song.

Because of our need to feel important in the grand scheme of things, we tend to like things that make us feel unique and powerful, while hating that which makes us a part of the larger universe and relatively inconsequential. We therefore make ourselves out to be different from the animals, denying that which is universal while focusing on what we consider to be our strengths.

This tribalism was once more focused, with our ingroup being whatever village or tribe raised us from childhood and the outgroup being anyone and anything different from that. Over that past few centuries, civilization has given us the ability to communicate with each other across the globe and learn about how similar we really are. But this has not yet extended to animals as a whole, so they are still viewed as "foreign" overall despite our now knowing much more about how similar we fundamentally are than we ever have.

In short, people view bestiality gross for the same reason that people a hundred years ago largely found interracial couples gross, or that people in the Indian caste system found the untouchables gross: because it gives them something to which they can feel superior, something which they can reject without understanding and think themselves holy about it.

Different people find different things to be gross just as different people find different things to be pleasant. It's a feeling, not a moral/ethical judgment (though of course people will often use it to justify the opinions they hold) and as such, there's not always a rationale behind it. Case in point: you might find all sex to be gross, but I know of countless people who do not find sexual activity in general to be gross at all.

My guess is that more than likely, it's not the physical act of a human having sex with an animal that disgusts people; it's the mental component of having sex that bothers people. Bestiality is seen as rape in much of society's eyes and rape is seen as a violating, traumatic, and disgusting act. Therefore, many people view humans "raping" animals as a vile and disgusting act.

I applaud you! I want to know the texture of each species' vagina. Is human vagina the most pleasurable?

God made dirt, and dirt don't hurt >:)

I find it hard to rationalise my own emotions, so I suspect they don't know why they find it disgusting in the same way I don't know why I find horses and dogs sexy. (Saying "because I'm a zoo" is a tautology, not a reason).

If I'm just hypothesising, some reasons that come to mind:

• They were brought up to think that
• They are closet zoos themselves
• Tribalism (some people try to denigrate Islam by saying "Muslims first invented condoms made from goat intestine, but 800 years later the British removed the rest of the animal", and that only works as denigration if bestiality is frowned upon)
• Genuine concern for animal welfare, either thinking animals are too small (which I see plenty of us caring about), or that they are fluffy minors (and if anyone is after a fluffy minor, I see them kicked out pretty quick)
• Mentally associating all sexual deviancy as equivalent, from anal to zoophilia and everything in between.

So, here is a story of "disgust".

The first time I went down on a mare I had to overcome the idea that she was somehow dirty, that the act was disgusting, and I even had a slight physical reaction to her as i approached. So, here is the think, I knew none of that was true in a factual sense. I had cleaned her, smelled her, tasted her and so forth. Yet in an emotional sense, before the act was consummated, I had those feelings. (Never about penetrative sex however, which is interesting)

The act itself transformed the instant it was performed and is now one of my and their favorite activities. There is no question in my mind now that it was ever really disgusting. We are trained to look at animals as dirty, and to look at dirty as bad. I think the whole caste system or interracial idea mentioned above explains it pretty well. What does it say about someone willing to cross that barrier to general society?

There's plenty of animals I'd find too gross to fuck. Including people.

To add to what /u/kynophile said so perfectly, one of the things we do to reinforce our "superiority" over animals is we infantilize them, we turn them into helpless babies that will never grow up in our eyes and thus remove all possibility of viewing them as equal, adult creatures with equally complex emotions, needs and desires. We neuter them, groom them, breed them into absurdly small and cute shapes to the point of causing them genetic harm. We pamper them, cuddle them and baby-talk to them and punish them when they behave "like animals."

The most absurd part of this is not even the human cultural attitude towards zoophilia, it's the way we mistreat and abandon these so-called babies when we tire of them. They are not only like playthings for people to project infantilism on, they are treated like broken toys when we grow bored and discarded in the most cruel and callous ways imaginable. Every day I see stories and videos on reddit about people doing unimaginably vile things to pets that we deliberately bred over thousands of years to be utterly dependent on us for care and love.

Humans are raised to find certain things gross. They do not actually know why nor have most of them given it much thought. We are trained from a young age "don't do that, that has germs, that is gross, etc." It is a psychological thing based in human instinct for interaction, but this does not make it okay to just go with either. The way I see it 'gross' is little more than a societal construct and holds no water on anything. Things are still unsanitary, but nothing is gross to me. Most sex with animals is not any more unsanitary than most sex with humans.