I understand the cause of that discussion.
Just like loli content (visible underage, which means, as long as someone seems underage, they are, regardless of whatever is told by the developer), bestiality is illegal in most western communities.
This includes depictions, written stories, basically any kind of artwork (again in most western countries).
This is one of the reasons why I wonder that the staff is doing nothing about it. This page could be shut down in minutes if authorities actually found out that there is so much of this content here. (bestiality does not include human-looking cowgirls, catgirls, tentacles, etc, they have to be actual animals).
I've seen a number of games here which 100% would cause trouble, there is actually a game where a daughter is told to be 14 years old. Doesn't matter though. Make a girl look pre-pubescent (fx, 12 yo), she actually is considered that in the eyes of the law, no matter if you tell the player that she is 18.
Not very on topic, but it's the same with bestiality. Any country where it's illegal could close down this site (it is illegal in all US states and territories except one or two and all EU countries). And every one of these countries ban even depictions if the depiction is made to be lewd (ie, visually showing the act).
So, I advise you to be careful including animal sex in games, just as the other stuff I wrote about.