Q. Why is my cat eating grass and getting so fat and heavy all of a sudden, his only 1 year and half?
DR. CHRISTIE LONG, D.V.M., C.V.A.
A. First of all, eating grass is not necessarily abnormal behavior in a cat, as long as he's not eating excessive amounts and throwing up excessive amounts. Cats will nibble on a little grass, but if you're seeing him throw it up daily or so something isn't right.
As for why he's getting heavy, I'd have to go back and ask you how much you feed him? Do you feed dry food only? Do you fill a bowl and leave it for him? Neutered male cats are prone to obesity, so you kind of have to be careful how you feed him. I don't recommend free feeding, and I would consult the food bag and feed accordingly. I would also consider switching to web food, as it's less calorically dense than dry.