“Benadryl is a great medication for use in dogs with mild-to-moderate allergies. Seasonal allergies, food allergies, environmental allergies, and allergic reactions to snake and insect bites all respond to Benadryl in most cases.”   https://www.akc.org/expert-advice/health/benadryl-for-dogs/

“many formulations are combined with other medications such as Tylenol so make sure Benadryl tablets contain only diphenhydramine.”

“Some Benadryl products contain decongestants as well, and these can be dangerous for dogs.”

Benadryl - a milligram per pound of body weight.

https://healthypets.mercola.com/sites/healthypets/archive/2018/08/19/dogs-can-be-stung-by-insects.aspx

 

Do not give Benadryl to dogs with glaucoma, high blood pressure or cardiovascular disease.

“1 mg per pound of body weight, given 2-3 times per day.

https://www.petmd.com/dog/general-health/can-you-give-dog-benadryl

 

If your dog has any of the following conditions, only use Benadryl after consulting your veterinarian:

 https://www.akc.org/expert-advice/health/benadryl-for-dogs/