Is it Safe to Give My Dog Benadryl?

June 26, 2017

give my dog benadryl
During allergy season, many of us rely on Benadryl to ease sneezing, itchy eyes, and scratchy throats. You may notice symptoms of seasonal allergies in your pup and wonder whether this miracle drug could offer him or her relief, too. In short – yes. However, extreme caution must be taken when offering your dog over-the counter medication. Check the dosage carefully and consult with your veterinarian about appropriate use — especially with puppies, elderly dogs, and pets with chronic illness. Pregnant and nursing dogs should not use Benadryl, as it is passed through mother’s milk to the pups.

Benadryl is available as an oral medication, a topical solution, and injectable (from a veterinarian). The standard dosage for oral Benadryl for dogs is 1 mg per pound of body weight two times per day. The most common form is liquid, but 25 mg tablets (the dose for a dog that weighs 25 pounds) are also available. Giving oral medicine on an empty stomach is usually fine, but giving it with food or after a meal is preferred. This can help prevent reactions such as drooling and vomiting.

You may find that your dog dislikes the taste of liquid Benadryl, and you may need to get creative. Disguise the liquid in a snack, or opt for the tablet variety. Benadryl is also available in cream, gel, stick and spray for topical use on itchy dogs and those exhibiting inflammation. Use on fleabites, cuts, rashes, and other skin irritations. Be sure to follow the directions on the package, as you can overdose with lotions as well as with oral medications.

Benadryl in all forms takes about a half hour to kick in, so be patient in expecting results. Do not increase the amount you give your dog without a veterinarian’s direction and supervision.

Common Uses

Benadryl’s active ingredient, diphenhydramine, is an H1 antagonist. It’s used to combat histamines that cause allergic reactions to things in the environment. Benadryl can relieve inflammation and reduce symptoms of allergies like itching, biting, and watery eyes. The drug causes drowsiness, so it is occasionally used to relieve anxiety, especially on trips. Benadryl’s active ingredients are similar to those used in popular over-the-counter sleeping aids.

Benadryl can also be used to treat inflammation after a dog receives vaccines, as well as for insect bites, rashes, vomiting and motion sickness. In special cases, Benadryl is prescribed to treat side effects caused by mast cell tumors.


The effectiveness of Benadryl may lessen with long-term use. Dogs with long-term needs should rotate Benadryl with other antihistamines. Check with your veterinarian for guidance. If your dog takes other medications, be sure to discuss using Benadryl with his or her veterinarian. When taken with Benadryl, some medications can cause a stronger than typical reaction, including a sense of drowsiness or that “spaced out” look. Other side effects include dry mouth, urinary retention, and occasionally diarrhea, vomiting, and loss of appetite.

Signs of an overdose can include muscle tremors, rapid heartbeat, labored breathing, extreme energy loss, confusion and a fever. Dogs can experience seizures, circling and disorientation in extreme cases, and should be taken to a veterinary hospital immediately for emergency treatment. The ASPCA sponsors a poison control hotline, which includes Benadryl overdose support. Call 888.426.4435.

Giving Benadryl to your dog is usually safe and effective when used properly, but always be prepared for side effects and emergencies that can be experienced with the use of drugs. If your dog is itching and biting at his or her skin more than usual, read our article on “How to Know if Your Dog Has Allergies.”

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