I don't know about horses but I know dogs generally love performing (think only one of the dogs I have ever had cba, and I had one that would attempt to do literally anything at all for the possibility of food, sadly that one was as thick as three bricks and it was nigh on impossible to get him to understand anything XD).
I used to do circus, great fun :D though being children at the time we didn't do dome of death, have seen that and it's both cool and terrifying to watch O_O