What causes hives on dogs?
Hives are an allergic reaction to being exposed to something. Have you used a new cleaning product or given him a new food. My dog used to get hives when we used a particular wood polish on the paneling and he used to sniff it. In most cases it is not life threatening but if you see him have a more serious reaction such as foaming at the mouth, heavy breathing or any other unusual reaction, do take him to the vet immediately as it may be a form of anaphalctic(sorry brain not working for spelling) shock. Unfortunately with allergies especially in pets it is a process of elimination to find out what caused the reaction.
