It's not a racehorse, but the horse I ride has 2 turkeys, 5 hens, 1 rooster and 2 kittens. The kittens weren't bought "for" him, but the other buddies were because he's a bad spooker.
The kittens follow us while we're out riding. The horse just started accepting the turkeys and chickens and keeps trying to smell them, but they run away whenever he gets too close so he trots after them.
