I have a 3 month year old pit bull and just yesterday he was jumping around every where and eating well but today he isn't eating at all, he only drinks water and he hardly even gets up. Also, he's nose is dry. What should I do?:confused:

Is he three months or three years old?

Either way, that drastic a change would have me taking him to the vet (or at very least calling them). It could be allergies. It could be something he got into. It could be an illness.

Is he going to the bathroom okay? Does he seem to be in distress-unable to find a comfortable position, heavily panting, eyes glassy or glazed, abdomen distended or tender, etc.

Yes, you should definitely contact your vet. Is it really hot where you are?
Has he been vaccinated for Parvo yet? When did the vet see him last? If his stomach is protruding “bloated” looking, you need to get him to the vet ASAP. If he isn’t drooling or panting, or showing any other symptoms of distress, I would keep a close eye to make sure he stays hydrated. Give him pedialyte if need be. As soon as he stops drinking you will need to contact your vet. Puppies are at the highest risk for developing de hydration.