Home Doggy Blog Dog Health Benadryl For Dogs – Usage, Safety & Dosage

Benadryl For Dogs – Usage, Safety & Dosage

Benadryl For Dogs – Usage, Safety & Dosage

You’ve probably browsed your medicine cabinet at one time or another and wondered which medications you can give your canine companion, especially if you’re in a pinch. One of the safest, and perhaps very useful, over-the-counter products is Benadryl. What is it used for and what do you need to watch out for? Let’s find out.

In This Article

Uses of Benadryl in Dogs

Benadryl, or diphenhydramine, is an antihistamine used mainly in humans to help relieve the symptoms of allergies. It can be used in dogs for the same reasons, but that’s not where the benefits end. Antihistamines block the production of histamine, chemicals that recruit the immune system to react to an allergen in order to clear it from the system. Usually this brings sneezing, itching, watery eyes, etc, all of those symptoms that you associate with allergies. Blocking the production of histamine can reduce those symptoms.


Itching due to environmental or food allergies can be treated, in part, by antihistamines such as Benadryl. No one likes it when ort pups are itchy and uncomfortable. When allergens can’t be eliminated from your dog’s diet or environment, antihistamines are usually the mode of treatment.

Insects bites/stings

If your pup has ever gotten an insect bite or sting, you’ve no doubt experienced the rapid swelling that accompanies it. While this can sometimes be comical-think an oversized paw or lip- it can also be quite scary. Giving Benadryl as a first defense medication can help to reduce the swelling and pain associated with an insect bite or sting.

Allergic reaction

This goes along with the first two but still deserves its own mention. Benadryl can be beneficial if your pup is having an allergic reaction to anything from a medication, insect, food, or other chemical in the environment. These allergic reactions can bring out hives, difficulty breathing, or rashes.

Motion sickness

Benadryl is sometimes prescribed for those pups that turn a car ride into a slobbery, pukey mess in your backseat. Motion sickness is another use of antihistamines, like Benadryl, because they can decrease the amount of motion that a dog’s inner ear experiences, therefore, decreasing the amount of nausea and drooling that occurs with car trips.

Vestibular disease

Benadryl may also play a part in the treatment of vestibular disease in dogs. It may help based on the same guidelines as how it may decrease motion sickness.


Antiemetic is a fancy word for a medication that helps decrease vomiting. Benadryl may play a part in the treatment of vomiting due to kidney disease, gastroenteritis, hepatitis, and pancreatitis.


One of the more varied uses of Benadryl includes sedation to help relieve anxiety, itchiness, noise phobias, etc. Benadryl causes sedation by blocking histamines that are responsible for regulating the sleep-awake cycle. The benefits vary from dog to dog, so if your dog is experiencing anxiety, it’s best to see your veterinarian as there are more effective medications out there.

What is the Benadryl Dose for Dogs?

It’s important to always speak with your veterinarian before giving your dog any medication or supplement. Benadryl should be used only under the supervision of a veterinarian to ensure you’re giving a proper dosage and so that you know what side effects to watch out for.

Common Dosage for Dogs

That being said, the most common dosage for Benadryl in dogs is 1mg per pound of body weight. Since most Benadryl tablets come in a 25mg form, that means one tablet per 25 pounds. For dogs smaller than 25 pounds, liquid or children’s Benadryl will provide a more accurate dose.

Never give your pup Benadryl without first talking to your veterinarian.

Does Benadryl Have Any Side Effects in Dogs?

Benadryl tends to be a very safe medication for dogs. However, there are some dogs that are allergic to Benadryl and other antihistamines. Also, dogs with heart issues, changes in blood pressure, glaucoma, intestinal obstructions, hyperthyroidism or are pregnant should not use Benadryl. It should not be given with other sedatives, pain medications, or antidepressants.

The most common side effects of Benadryl in dogs are lethargy or sedation, which is great if that’s what you’re looking for. However, Benadryl can also the opposite effect and make your pup extra hyperactive for a short time.

Dogs may also have a little dry mouth, decreased urination and appetite for a short time. Benadryl usually takes about 30-45 minutes to take effect and 4-6 hours to leave the system.

How a dog responds to Benadryl will rely on the dosage they are given and the dog themselves. Just like in people, Benadryl may cause sedation one time and bouncing off of the walls the next. If you’re looking to use Benadryl in pup for a long-term issue, it’s best to talk with your veterinarian to find out if there is a better option.

Final Thoughts

Benadryl is a common over-the-counter med that veterinarians have pet parents give at home. It can work wonders as an initial treatment for insect stings or bites and can have some benefits for chronic itchiness due to allergies. However, since the other benefits are highly variable, your veterinarian will best determine if Benadryl is the right choice for your pup.