Has your dog been outside? Maybe he/she got into something or has an allergy to something? It could be many different things. If you changed its food, or gave him/her a bath, or dry skin or dermatitis. I would suggest you call your vet and see what he/she suggests. The dog may need to be seen. I would make sure that dog is eating well and drinking. If not call your vet they usually have an emergency # if you need to call. Other wise, wait and call in the morning. Maybe it is nothing. That is just what I suggest. It could be due to a bite, etc. Could be anything or nothing.
