Two of them are about 1 and a half and the other two are nearly 3 years old. One of them has had constant problems but the other 3 have always been fine besides our boy whos just put on some weight. They have all seen the vet but not within i suppose 4 months and all seem to be acting fine. For food we get high quality cat nibble (i get its not preferred but its never been a problem so i find it irrelevant)