I've noticed that my cat occasionally nibbles on the dogs dry food. I mentioned this to an acquaintance and she told me that her vet said it is very bad for the cat...that it can cause urinary tract/bladder problems...she did not remember the details but she sounded concerned about it. Should I heed that warning and keep a watchful eye on his food? It is a bit difficult because I always have some kibbles in the dish for him and there is no place to put it where the cat can't get at it, so if it is a serious hazard I can keep it empty and only feed him twice a day while I'm present to watch. He eats Performatrin Ultra, Lamb & Rice, hormone-free, all natural meal.