
Benadryl (diphenhydramine) is a common human antihistamine that may also be used in dogs. It is not recommended for use in cats except in extreme cases.
If your pet has allergies or is suffering from an insect bite, benadryl is often enough to help alleviate the symptoms. Just like in people, some animals are hyper-sensitive to it and may become very drowsy.
Please call your vet for directions and dosages so you may safely use it.