Humans have befriended animals for centuries. If you search online, you even find that some humans have intercourse with animals.
And yet, it's always out of wedlock. Why not marry these animals and do things legitimately?
I simply don't see how we can call ourselves a free society, when you cannot even marry for love whomever you please.
There are many rights groups who want to have, what we can call, "unconventional" marriages.
And yet, no animal rights groups have ever put money and effort into lobbying for animal marriage rights.
I think this is something that definitely warrants the attention of society as a whole. Discrimination against animals is an ugly thing.
Animals get mistreated, they get used, they get eaten. It's really an ugly picture of you think about it :(