Cat came home a couple of hours ago, limping a bit but asking for food and wandering around a bit. He ate about half his dinner then his limp seemed more pronounced. He went upstairs and jumped on the bed, then downstairs (following me). He was putting his sore leg down properly about once in every 4/5 steps. He then curled up and was shaking/shuddering, especially noticeable around his bottom/back legs.
I called the vet who said he's probably had an accident (he was very muddy with a scratch on his face so cat fight/got bumped by a car possibly?) Vet said it's best to monitor him as it's probably just shock making him shake. He's in a quiet dark room and the shaking seems to have eased off, but if I stroke him its more noticeable again.
I'm going to monitor him for another half hour or so, but at what point would you start to worry?