Benadryl Dosage for Dogs


Benadryl, also known by its generic name diphenhydramine, is one of the few over-the-counter drugs that vets routinely have owners administer at home. While it is typically well endured and has a large safety margin, there are a couple of things owners ought to keep in mind before dosing it at home.

Benadryl Usage

Benadryl is an antihistamine, obstructing the H-1 receptors on smooth muscle and blood vessels. A few of its most typical indications are the treatment of environmental allergic reactions, allergies to insect bites or stings, and pre-treatment of vaccine reactions. It likewise has some effectiveness in the prevention of motion sickness in dogs and as a moderate sedative.

How Does Benadryl Work?

Diphenhydramine is a receptor antagonist, which implies that the drug works by blocking the receptors that get histamines in the body. This alleviates a lot of the symptoms associated with allergic reactions, like itching, sneezing, and hives. The body still produces histamines, but the receptor villain blocks the receptors from signing up the histamines. It is a bit like the mail-person trying to provide mail to an already complete mail box. The letter arrives, however there is no room for it.


Benadryl is contraindicated with particular conditions, such as animals with glaucoma, hypertension, and heart disease. It’s constantly best to call your vet for assistance before administering any medication to your pet, including Benadryl.

Benadryl Dosage for Dog

The basic dose for oral Benadryl is 1 mg per pound of body weight, given 2-3 times a day. The majority of drug store diphenhydramine tablets are 25 mg, which is the size used for a 25 pound dog. Constantly double check the dose before providing an over the counter medication. In addition, many formulas are combined with other medications such as Tylenol so make certain Benadryl tablets contain only diphenhydramine.


Benadryl recommended dosage according dog weight and form of the medication.
How much should you give Benadryl to dog, depending on the forms of the drug and the dog’s weight.

What Does Benadryl Deal With In Dogs?

Benadryl is an over the counter antihistamine that relaxes allergies to environmental irritants, insect bites or stings, and particular vaccine responses. It has actually also been utilized as a sedative and to avoid movement illness. Though it is a human drug and not FDA authorized for dogs or other animals, it can be given safely with approval from your vet.

Benadryl is the brand name, not the name of the drug that treats allergic reactions. Diphenhydramine is the active drug in Benadryl that is safe for canines when given up the correct dose. There are numerous other brand names that make similar products, and there are other drugs under the Benadryl brand name that you should use caution to avoid. Check out the ingredients of the medication prior to offering it to your dog and ask your vet before giving any medication to your dog.

When Is Benadryl Bad For Dogs?

In some scenarios, Benadryl can be very harmful to dogs, which is why it is so crucial to consult your vet prior to giving your dog Benadryl. Here are a few circumstances where Benadryl can be harmful for dogs.

  • Medical conditions. Particular conditions, such as glaucoma, heart problem, or hypertension, can be gotten worse by Benadryl.
  • Other medications. Other drugs, even those that are over-the-counter, can trigger an unsafe reaction when combined with Benadryl.
  • Allergy. Paradoxically, some dogs can have an allergy to Benadryl.
  • Side effects. The most typical is sedation, but dogs can likewise experience changes in breathing, heart rate, and urination. Hardly ever, some may vomit or struggle with diarrhea.
  • Different solutions, brands, or items. Check out the active ingredients. Acetaminophen and Pseudophedrine are not safe for dogs, and they are included in some allergy medications. There are lots of Benadryl products, so ask your vet to make sure you are utilizing the proper one.
  • Overdose. An overdose of Benadryl can be deadly. If your dog consumes excessive Benadryl, call the emergency veterinarian or toxin control hotline at (888) 426-4435 right away. Symptoms of overdose include dilated pupils, constipation, rapid heartbeat, behavioral changes, and seizures.
  • Pregnant or nursing. Dogs that are pregnant or nursing should nearly never be given medication without stringent veterinary supervision.

Side Effects of Benadryl

There are side effects related to using Benadryl for dogs that all dog owners should be aware of. Much like people consult their physicians before taking a new medication, you must always contact your veterinarian prior to introducing Benadryl to see if it has any potential drug interactions with your dog’s other medications, or if it could aggravate a pre-existing condition.

If your dog has any of the list below conditions, only use Benadryl after consulting your vet:

  • Angle closure glaucoma
  • Extreme heart failure
  • Prostatic hypertrophy
  • Bladder neck obstruction
  • Seizure conditions
  • High blood pressure
  • Allergic lung disease
  • Pregnancy

Common side effects related to utilizing Benadryl for dogs consist of:

  • Sedation
  • Dry mouth
  • Urinary retention
  • Hypersalivation
  • Increased heart rate
  • Rapid breathing

Unusual side effects:

  • Diarrhea
  • Throwing up
  • Reduced cravings
  • Increased hunger

A lot of side effects happen within the first hour of direct exposure, so monitor your dog thoroughly during this time.

Benadryl Overdose in Dogs

It is possible to overdose on Benadryl. Signs of an overdose include hyper-excitability of the central nervous system (CNS) and can be deadly. Other indication to watch for are:

  • Rapid heart beat
  • Dilated pupils
  • Agitation
  • Constipation
  • Seizures

If you think your dog has overdosed on Benadryl, call your vet or emergency veterinary health center instantly.

Some dogs establish an allergy to Benadryl. If your dog begins having symptoms of an allergic reaction, look for veterinary care instantly.

As Benadryl for dogs is frequently utilized to treat allergies, keep an eye on your dog after giving Benadryl for the very first time to make sure that the allergy symptoms don’t aggravate.

When Does Veterinarian Should Be Involved?

Oral Benadryl is considered a moderate to reasonably effective antihistamine. If a pet is having an acute allergy with facial swelling or difficulty breathing, avoid the oral medications and go straight to the vet. Lots of allergic diseases need a combination of medications and treatment of underlying infections; if your animal is not reacting to the medication, speak to your vet for other options.

Reyus Mammadli
Having engineering and medical education, in recent years actively engaged in the study of the development, reproduction of domestic animals. Special attention is paid to the treatment and prevention of diseases of Pets.
Pet Health
Leave a Reply

  1. Geta Martins

    My dog hates eating Benadryl, but in some cases it’s needed since he’s a Boston Terrier and he’ll break out in a rash due to an innate sensitivity that he has.

  2. Dr. Unker

    Every pet person ought to own “The Pill Book Guide to Medication For Your Dog And Cat, Bantam Books. p 198, Benadryl (Diphenhydramine) there are lots of preventative measures and possible side effects such as Common: drowsiness, dry mouth and urine retention. Uncommon decreased hunger, vomiting and diarrhea.


    Dogs: 1-2 mg/lb 3-4 times a day

    Felines: 1-2 mg/lb 2-3 times a day

    Drug kind: Diphenhydramine can be found in a variety of forms for internal and external use. The pediatric elixir or syrup (12.5 mg/ml) might be the most convenient form to administer orally to dogs and felines. It is also available in 25mg and 50mg tablets and capsules and injectable.

  3. Susie Richardson

    It is safe to give most dogs Benadryl however this is something best asked of your veterinarian as your dog may have a condition that may hurt your dog. I have actually offered Benadryl to my Blue Tick Coonhound to try to stop his chewing of his paws (my veterinarian recommended me to try it and provided me dose details), nevertheless a vet likewise told me to give Benadryl to my 20 pound dachshund and it had an awful effect on him. While my larger dog got a little sleepy my small dachshund had the opposite response and he was restless, his heart was pounding quickly and it didn’t assist him at all. I never ever offered my dachshund Benadryl again after the first time due to the bad side effects. Please contact your vet about offering Benadryl to your dog and likewise about the dosing directions.

  4. Natasha Harris

    Benadryl is definitely safe to give to dogs in the appropriate dose, for instance I give my 22 LB dog a single 25 mg dose of Benadryl. Excessive Benadryl will cause seizures. More than likely it will not eliminate your dog however you truly don’t wish to offer to much since seizures are severe. If you have a Brachycephalic dog (pugs, frenchie’s and other short nosed dogs) that gets an allergy that could kill your dog in a brief time which is really when Benadryl is available in very handy. I am not a veterinarian so please call your vet and ask the right dosage for your dog. Then go out and get some since in certain situations Benadryl is a life saver.