He walks with a limp of the front legs. The previous time, after a few days' limping, he started to literally keep his head down, shoulders way up. He made the impression that it hurt him very much to keep his head up, for he even ate while lying down on his tummy. He does not suffer from lack of appetite or constipation, but he is very lethargic for a tom of his age. He is also much less affectionate than usual. The two previous times he suffered from whatever he suffers from, it passed without treatment or medication (our vet didn't have a clue so couldn't do anything), but this does not mean that it does not have us worried!