Why does a dog shake its body?

A dog shaking its body may be from cold, fear, parasite bites, or pain from other illnesses. First, with big temperature swings or very cold weather, cold-air stimulation can cause shivering; owners should keep the dog warm.

Second, a frightened dog may tremble in fear and needs comforting. Also, parasite bites causing itchy pain can make it shake; check for bite marks and deworm promptly. Finally, body pain may cause shaking; if appetite and spirit drop, take it to a vet.