My cat Leo had all of a sudden started shaking and running through the house, then hiding for hours at a time. He won't cuddle or even eat a treat. He does go outside, but not all the time. He has all his shots. What could have happened to make him act this way?

How long has this been going on? Any changes in the house? When was his last vet appointment?

Have you found out what is wrong with your cat? My cat has started doing that.