While Benadryl is not FDA-approved for use in canines and other animals, it can still be administered to dogs under certain .

Benadryl, the brand name of the generic antihistamine diphenhydramine, is not labeled for use in dogs but has remained ... There is a liquid form available if you have a small dog.

Benadryl is a human medication that can be used in dogs to relieve allergy symptoms. But you have to be sure you're giving the right dose for your dog's size. (Photo Credit: E+/Getty Images ...