Has anyone had any luck settling a cat's diarrhoea down? Our cat has a huge appetite (I posted a few days ago that he'll quite happily eat 5 pouches a day!), but also seems to have chronic diarrhoea. It'll settle for about two days, then start up again. It really doesn't seem to be related to the food - we've tried Royal Canin Digest Sensitive, Hills Science and Whiskas, and nothing seems to make him particularly much worse or better.
The breeder used to feed him on Whiskas, and said he was absolutely fine on it. He's also been to the vet twice and they can't find any underlying cause.
I'm going to move him to a grain-free food just in case, but because of what the breeder said about him being fine on Whiskas, I'm not too hopeful. I'm really hoping it's just about finding the right food, and not that he might be poorly all his life.
Has anyone else had anything similar? What did you do?