Well there are teams that have live lions, bears and tigers, and at least one has a buffalo. There are lots of live dog mascots (including quite a few different bulldogs), there is at least a few bighorn sheep, a few eagles (including a Bald), a razorback, a few horses, a texas longhorn, rooster, mules, shetland pony, Northern Goshawk, bobcat, and possibly more.
Yeah it's very sad, and I hope they can find the culprit. I would however not assume that this is a sports rivalry, because it could very well be something else entirely