The world of My Little Pony: Friendship Is Magic raises a lot of questions about animals. I mean, they're talking horses, but they also have a complicated economy and businesses, all built on the very shaky premise that a bunch of talking horses are going to build an entire financial system around selling cakes, and it only gets more complicated when you throw in the fact that there are other animals involved. Take Applejack for instance. She owns a farm, and while she obviously primarily raises apples, she's also got a herd of cattle -- cattle who also talk, and seem to have hopes and aspirations of their own.
What I'm getting at here is that the relationship of the ponies to other animals is pretty complicated, and it's only set to get more so in next week's My Little Pony: Friendship Is Magic #24, when Fluttershy and the Cutie Mark Crusaders are dragged through time by a semi-reformed chimera to see some dangerous animals from Equestria's past.