What Happens If You Have Sex With An Animal?


If you're on a quest to find your soulmate it’s expected that you would cringe at the idea of finding beauty in a beast. But we were all for Belle falling in love with a water buffalo, amirite? So what are the issues with bestiality, anyways? What would actually happen if you had sex with an animal?

Before you start flirting with huskies on the street, biological mechanisms are in place to prevent sex between different species. If two different species' sperm and egg can’t fuse this is called a prezygotic mechanism. For example, this can happen if two closely-related species have incompatible sex organs (aka Mechanical Isolation), two distinct species live in such different locations so they can never bang (aka Habitat Isolation) or they have different mating rituals so are never even interested in trying (aka Behavioural Isolation).

Even if two different species end up managing to have sex, it’s unlikely the sperm and egg would produce an offspring. In the case of bestiality with you and a closely-related species like a baboon, one study showed that human sperm couldn’t attach to the protein surface of the eggs of baboons. Therefore, there would be no fusing and the first phase of fertilization could never be completed. So no part-baboon part-human babies will ever roam this planet.

But in some cases, a successful offspring can be produced by different species. For example, a male lion and female tiger can produce a Liger. This is where postzygotic mechanisms come into play: these are mechanisms that prevent the survival of an interbred offspring. For instance, when you cross a horse and a donkey you likely end up with a sterile mule. So the mule exists but can’t have babies itself.

Other postzygotic mechanisms include hybrid inviability, where a successfully fertilized egg doesn’t develop past early stages. Or hybrid breakdown, where the offspring itself can have kids but generations after are sterile and incapable of producing children. All in all, prezygotic and postzygotic mechanisms ensure that if different species do have sex it's hard for them to successfully reproduce.

But sometimes, animals labelled as different species can still mate because they share a relatively recent ancestor. Like when us homo sapiens mated with neanderthals.  The hypothesis is that female humans breeding with male Neanderthals were able to generate fertile offspring, but female neanderthals who mated with male humans were either rare, absent or infertile. There are many conflicting theories about why and how we hooked up with neanderthals - but one reason may have to do with the fact that they are kind of FINE.

Being a human who engages in bestiality comes with dangers.  One study shows that males who had sex with animals were at a higher risk for penile cancer than males who didn’t. This is probably because microtraumas on the penile tissue are produced during sex. This expose the human tissue to animal secretions and other infectious agents that can lead to cancer. Several other case studies show colorectal trauma and harmful bacterial infections are also possible after sex with an animal.   

So, ugh, why do people do it?  One study identifies several motivations for bestiality. For instance, there may be situational reasons, where people have limited access to human partners; or financial incentives, or where people have sex with animals for pornography or for sex shows. There may also be cognitive impairment, emotional immaturity, and dopamine dysregulation motivating the act as well.  And there are some reported cases of “zoophiles,” who feel affection and intimacy with an animal. One case study even looked at a man who left his wife in order to live with horses he had affection for. So, it turns out Belle wasn’t the only one who fell in love with a beast.

Mitch Moffit