Believe it or not, the vet told me to give him a teaspoon of canned pumpkin a day. Then maybe work it up to a tablespoon. Bo eats a lot of weird stuff, so I think I'll try that. If he won't eat it, she said I could also switch him over to SD hairball formula. My cats eat the regular SD food, so that is my other choice if he won't eat the pumpkin.