Franklin Animal Clinic Inc.

1623 Pittsburgh Road
Franklin, PA 16323


Benadryl (Diphenhydramine)


In pets, Benadryl is most often used to decrease or alleviate itching due to allergies. It is used in dogs and cats that are having upper respiratory symptoms such as sneezing.

  • Generally, Benadryl has few side effects. The most notable is drowsiness.
  • Pets that are taking anti-anxiety medications may become more drowsy if taking Benadryl.
  • Cats do not often like the liquid Benadryl. Chlortrimaton may be a better antihistamine to use.
  • If you have any concerns about giving your pet Benadryl contact your veterinarian first.


To use this "dose caluculator" just enter your pet's weight (in pounds) in the yellow box below (place your cursor in the yellow box and "left click" your mouse...this will select the box...then you can enter the weight) and press enter. If you are unsure of your pet's weight you can use a household scale. If you chose to estimate a weight make sure to under estimate the weight. When in doubt it is always better to give less of a medication instead of more. 

This information is intended to provide general recommendations regarding the use and dosing of this medicine. Any medication, including OTC products should not be used without first consulting your veterinarian. This dosing calculator is provided to ensure that you give the correct dose of medication to your pet.