My s-i-l's cat used to throw up because of eating too fast, vet recommended that she put a golf ball in the dish so the cat had to eat around the golf ball (or ball of some type) and would slow down. She hasn't had any problems with her throwing up since.
Tonga throws up because of hairballs, so we started giving him the hairball treats (yellow bag - Friskies) and he doesn't throw up as often. Put him on the indoor formula (Eukanuba) and he has lost a lot of weight, hasn't thrown up in a long time. So it might be a variety of everything.
Thanks! I'll try the ball thing. I'll give him the hairball gel just for the helluvit. :shrug: Can't hurt him.