Cat can't jump up
My cat is a 13 year old, indoor/outdoor neutered male. He was missing outside for a day and a half recently. He seems to be fine. Eats well, drinks water, uses litter box. Purrs. Except he doesn't seem able to jump on on my lap, up on the bed, etc. He wants to do it but hesitates and stops. There does not appear to be any injury to his legs or anything. If I pick him up, he's fine and has no problem getting down. Could he have strained some muscles while he was missing? How long should I let this ride? Thanks.