Can You Give a Dog Benadryl?

Benadryl is an effective medication for allergies and other conditions; most veterinarians allow its use in canines. So, can you give a dog Benadryl, the answer is that generally speaking, yes, there should be no problem in administering Benadryl to your dog.

This is certainly a question many veterinarians are often asked. However, Benadryl, which is diphenhydramine in the US and Canada, is usually well-accepted by dogs and it is easily available without a prescription because it is an over-the-counter (OTC) medication. Benadryl is an antihistamine; which means it counteracts the effect of histamine which causes symptoms such as itching.

Most OTC medications are prepared for adult human consumption, and dogs usually weigh considerably less than humans, so the amount given to your dog may need adjustment from package recommendations, especially when given to puppies and smaller “toy” adult dogs. Your veterinarian will tell you how much of the medication to administer.

Benadryl is given to dogs to treat several medical conditions. The most common are allergy symptoms such as itching, ear infections, and asthma-like symptoms, runny or stuffy nose, coughing, and sneezing. However, Benadryl may also be given for other conditions such as non-allergenic causes of itching, motion sickness, insect bites, bee and hornet stings, and irritation around the dog’s anus. Benadryl is also a sedative and can be used to calm agitation, travel anxiety, and to treat insomnia.

Note: Benadryl (diphenhydramine) has been used sometimes for snake bites; however this is an uncertain practice and should be avoided.

Benadryl is usually quick acting and relief will often be clearly noticed within 30 minutes after administration. That said, in some cases, it make take a week before results are evident. However, there is no question should you ask, can you give a dog Benadryl. But there are other questions you should ask your vet: how much Benadryl can I give my dog, and is Benadryl safe for dogs.

How Much Benadryl Can I Give My Dog?


The general guideline for how much Benadryl can I give my dog is 1mg of Benadryl (diphenhydramine) for each pound of body weight, 3 times per day (which means every 8 hrs). As an example, a 20 lb dog could be given 20 mg of Benadryl 3 times per day. However, please note that it is strongly advised that you get professional advice from your vet before administering any medication to your dog.

Benadryl is normally given to dogs in two methods:

  • By Tablet: Crush the tablet and mix into the dog's food.

  • By Liquid Gel Capsules: Drip the liquid into the dog's food.


Some dogs are smart and have figured out that medicine may be hidden in their grub. But, even smart dogs love certain kinds of food better than others. If your dog searches for pills in their food, hide the pill or place the liquid in one of their favourite foods. They are more likely to gobble it down without thinking.

There are other methods of administering this medication in some circumstances your veterinarian may advise, these including rectal suppositories and by injection. However, these methods are not normally as preferred as tablet or liquid gel capsule.

Benadryl can also have side effects in dogs that take other medications. Make sure your vet knows of all the medications your dog is currently taking. This is important information in determining how much Benadryl can I give my dog, or if you can give it at all. This is especially true if you have an older dog that is taking other medications. Your vet will advise you on the correct dosage, as this may vary due to interaction with other medications and other factors.

Is Benadryl Safe for Dogs


Well, is Benadryl safe for dogs? the answer is yes, Benadryl is generally very safe for healthy dogs. Benadryl has been used for allergy control since 1946, so it has a long history of use. This medication has been also been studied for decades and it has been noted as normally providing few side effects when used on a healthy adult dog of medium to large build.

Benadryl is normally well-tolerated when taken with flea and heartworm medication as well as steroids. Be aware that some OTC variations of Benadryl have additives that should be avoided, such as decongestants, painkillers, added sodium, alcohol, or sugar. It is important that the only active ingredient used for dogs should be diphenhydramine.

If your dog has a serious medical condition then it is important to ask your vet, “can I give my dog Benadryl.” This is because some pre-existing medical conditions can be a concern when taking this medication. Benadryl is not normally given to dogs with high blood pressure, cardiovascular disease, glaucoma, prostatic disease, urinary obstruction, hyperthyroidism, or dogs that are pregnant or if your dog is nursing puppies.

I hope I have answered your questions concerning Benadryl.