Veterinary questions? Ask a Vet for Answers ASAP
You are through to Dr Coles. I am a UK based vet. Sorry to hear you are having problems with Bernie. There are many different reasons that a cat can be quiet or not himself. The fact that he doesn't want to come out of bed and seems withdrawn is quite a concern as this does suggest he isn't feeling well. If there is a not very nice cat on the street, it is very possible that they may have gotten into a fight. This can cause abscessation to develop (under the skin sometimes it is not visible) which can cause them to have a temperature and not feel well. I would recommend that you book him a vet appointment for tomorrow so that he can be assessed. He may need blood tests if nothing obvious is found on examination. For tonight I would advise offering him some bland food such as chicken/white fish and keeping him somewhere warm/quiet with water in easy reach.