[thaliasmom]

Hmm...does he know "no"? If so, I'd begin reprimanding him for that sort of behavior! The alternative is to give him an alternative behavior - when he sees horse, to heel, or whatever. Eventually (and probably quickly, sounds like he wants to please!), he'll offer it whenever he sees the horse in question. This was suggested to us when we were having problems with the puppy and the cat, and it really worked. And we were able to transition from "offer that behavior every time" to a more general level of tolerance and existence.

I have horses and dogs myself, so I know how important and tough this can be! Good luck!