How long before a car ride should I give my dog Benadryl? What to Know

Is 25 milligrams of Benadryl safe for a dog?

According to the Merck Veterinary Manual, one 25-milligram tablet of Benadryl two to three times daily is the correct dose for a 25-pound dog. So, if your pup weighs 25 pounds or over, then a dose of 25 milligrams several times a day is perfectly safe. Small dogs should be given children’s liquid Benadryl, as it contains a lower concentration of diphenhydramine and makes it easier for you to administer the correct dosage to your pup.

Clubs Offering:

The temptation to reach into our medicine cabinets to treat our pets can be dangerous. Humans and dogs react very differently to medications, which is why veterinarians caution dog owners against making independent decisions about how to medicate their animals. However, some human medications are safe for use with dogs, as long as they are used appropriately.

Veterinarians use diphenhydramine, commonly known by the brand name Benadryl, for dogs on a regular basis to treat allergies, travel anxiety, and motion sickness. While you should always consult with your veterinarian before giving your dog a human medication, here is what you need to know about using Benadryl for dogs.

Benadryl is the brand name for the active ingredient diphenhydramine HCl. Diphenhydramine is a first-generation ethanolamine-derivative antihistamine, which is the scientific way of classifying antihistamines that can cross the blood-brain barrier – making them very effective but also increasing risks of adverse side effects. While Benadryl is not yet FDA-approved for veterinary use, it is considered safe for use in dogs and cats and is commonly used in veterinary practices across the U.S.

Diphenhydramine works by blocking the receptors that receive histamines in the body. This relieves many of the symptoms associated with allergies, like itching, sneezing, and hives. The body still produces histamines, but the receptor antagonist blocks the receptors from registering the histamines.

How Do I Figure Out The Correct Dosage Of Benadryl For My Dog?

So, Benadryl is safe for dogs—but now it’s time to talk dosage.

Just like with any human medication, the dose of Benadryl for dogs is super important. Too small a dosage and they won’t get any relief from their symptoms. Too high a dose and you run the risk of serious side effects or overdose.

So how, exactly, do you find the right dosage for your dog?

The standard dosage guidelines are 1 mg of Benadryl per pound of body weight two to three times per day. So, if your dog weighs 25 lbs, you can give them a 25 mg dose of Benadryl for dogs every eight to 12 hours. If your dog weighs 5 lbs, you’d give them a 5 mg dose.

Again, before giving your dog any medication, you’re going to want to talk to your vet to get the green light—and that includes on how much Benadryl to give your pup. In certain cases, your vet may recommend upping the dosage (for example, if your dog gets bit by a pup), or lowering the dosage (for example, many vets recommend children’s Benadryl, which has smaller amounts of Diphenhydramine HCL, for dogs like chihuahuas) to best suit your dog and their needs.

Benadryl For Dogs? Dr. Dan Explains

Last updated Feb. 15, 2022. Reviewed for accuracy on Dec. 11, 2019 by JoAnna Pendergrass, DVM

Benadryl is not yet FDA-approved for veterinary use, but it is generally considered safe for use in dogs with mild-to-moderate allergies. Benadryl is a brand name for an antihistamine (diphenhydramine HCl) that can help alleviate symptoms of allergic reactions and even anxiety. Histamine is a substance released by mast cells (a type of immune cell) and is responsible for inflammation and other allergy symptoms. The active ingredient in Benadryl is diphenhydramine, which works by blocking histamine receptors on a cell’s surface, meaning that the receptors cannot ‘accept’ histamine that tries to attach and trigger an allergic reaction.

Symptoms of allergic reactions that can be treated with Benadryl include hives, swelling, and itching. Severe reactions, like anaphylaxis, can be life-threatening and should be treated by a veterinarian (who may give an injection of diphenhydramine along with other emergency injections).

Many veterinarians approve Benadryl for home use as a regular go-to treatment. It may be suitable for: