This happens too often – by the time an owner realizes that his cat is sick, the cat is very sick. Cats tend to hide their illnesses, and they even hide when they are sick. But many problems are best treated when they are caught early, which means you are your cat’s most important health care provider. You’re the one who sees him every day and decides when he needs to see the vet. Don’t ignore what he’s trying to tell you – or try not to tell you. Here are some of the clues you should look for.