Can I Give My Dog Benadryl?

Can I Give My Dog Benadryl?

Allergies in dogs are relatively common and are usually simple to treat. Certain breeds are predisposed to developing allergies, but any dog can have an allergic reaction to something. When a reaction happens, every dog parent must understand how to treat it, whether with Benadryl or other natural alternatives.

While Benadryl is a known treatment for human allergies, most vets agree that it’s safe and effective for dogs as well — they react to the same allergens that we do.

Let’s look at everything related to Benadryl for dogs, from how it works to the side effects and dosages.

Did you know that CBD can help alleviate allergy symptoms in dogs? Check out the best CBD products!

Related: Our Thoughts on Organic Dog Food

What Is Benadryl?

Benadryl is a brand name for an antihistamine that uses diphenhydramine HCL as its main and active ingredient. Diphenhydramine HCL is an ethanolamine-derivative antihistamine, meaning that it is scientifically classified as being able to cross the blood-brain barrier. Crossing the blood-brain barrier means that the medicine works extremely efficiently, but it can also come with the chance of more adverse side effects.

Even though Benadryl has not been FDA-approved for animals, it is widely considered safe for dogs and cats to consume. Veterinary practices commonly use Benadryl across the United States to treat dogs and cats’ various symptoms and conditions.

How Does Benadryl Work?

The main ingredient, Diphenhydramine HCL, acts as a receptor antagonist. It works by blocking your dog’s receptors that receive histamines (the compounds that initiate a response to an allergic reaction.) Many symptoms that get associated with allergies like sneezing, itching, and haves get instantly relieved by blocking those receptors.

Benadryl doesn’t stop your dog’s body from producing histamines, but it blocks them from being registered by the receptors. Imagine trying to add more clothes into a full suitcase — the clothes are there, but there isn’t any room left for them.

What Does Benadryl Treat in Dogs?

Many pet owners treat their dogs with Benadryl to relieve mild and moderate symptoms from seasonal, food, and environmental allergies. Benadryl is also known to treat allergic reactions from bug and insect bites efficiently. The medicine is also commonly used to alleviate itchiness caused by a dog’s skin allergies.

Benadryl and diphenhydramine can also reduce other allergy symptoms, like:

  • Itching
  • Hives
  • Inflammation and swelling
  • Redness and hot spots
  • Runny eyes and nose
  • Sneezing
  • Coughing
  • Anaphylactic reactions

Other than allergies, Benadryl helps relieve anxiety symptoms and motion sickness in pets that are associated with traveling and car rides.

Mast cell tumors produce and release histamines in a dog’s body, and since Benadryl works by blocking histamine receptors, it can help mitigate those effects.

Benadryl also gets used sometimes during heartworm treatments — it helps prevent some of the allergic reactions associated with the treatment.

Types of Benadryl for Dogs

There are multiple types of Benadryl, and most, but not all, of them are safe for use in dogs. The most popular forms of Benadryl are:

  • Tablets: Benadryl tablets typically contain 25mg of Diphenhydramine HCL. Most dogs don’t enjoy taking pills or tablets, so you’ll probably have to hide the Benadryl in their food or treats. Time-release tablets should not be given to dogs; they are harder to dose correctly because Benadryl is absorbed differently in dogs than in people.
  • Children’s liquid Benadryl: If you want to use liquid Benadryl, go with the children’s formula. Children’s Benadryl contains no alcohol and is less concentrated with a lower dosage range; it’s easier to measure out an exact dose, which is extremely helpful for owners of smaller dog breeds.
  • Spray: During an emergency, when your dog is having trouble breathing due to swelling from an allergic reaction, you can use Benadryl spray. Do not use the spray on open wounds; this can cause stinging and discomfort for your pet.
  • Topical: You can also find Benadryl in a cream or gel to apply directly to a dog’s itchy skin. Topical creams are fine to use every once in a while, but prolonged use can cause irritation.
  • Injections: Benadryl injections can get administered by vets to reduce the effects of a severe allergic reaction. The injections are typically given in the veins, muscles, or underneath the skin.
  • Adult liquid Benadryl: Do not give regular liquid Benadryl to your pets; it contains alcohol and is toxic to them!

Side Effects of Benadryl

A dog getting sleepy after taking Benadryl

If you are considering using Benadryl to treat some of your dog’s allergy symptoms, it’s essential to know some of the potential side effects. If your dog has certain conditions or is taking other medications, you should talk with your vet before introducing them to Benadryl.

Consult your vet before using Benadryl if your dog has any of these conditions:

  • Angle-closure glaucoma
  • Prostatic hypertrophy
  • Severe heart failure
  • Seizure disorders
  • Bladder neck obstruction
  • Allergic lung disease
  • Hypertension
  • Pregnancy

Most side effects happen within the first hour of taking Benadryl, so watch your dog and monitor for these common symptoms:

  • Tiredness
  • Dry mouth
  • Hypersalivation
  • Fast heart rate
  • Rapid breathing
  • Urinary retention

Those are the most common side effects, but in rare cases, you may see:

  • Vomiting
  • Diarrhea
  • Change in appetite

What Is the Benadryl Dosage for Dogs?

The standard Benadryl dosage for dogs is 1 mg per pound of their weight, and the dose can be given two to three times per day as needed 8-12 hours apart

When using a topical Benadryl, make sure to test a small area first and watch for any allergic reactions your dog might have to the cream. Topical Benadryl should not be used if you are giving your dog Diphenhydramine in another form as well.

If your dog needs an injection of Benadryl, the vet will determine the dosage that your dog needs based on their symptoms.

To determine the Benadryl dosage that your dog needs, refer to this chart:

Dog Weight Tablet (mg)

Every 8-12 hours

Children’s Liquid (ml)
Every 8-12 hours
1 lb – 10 lbs 1 mg – 10 mg 0.4 ml – 4 ml
10 lbs – 20 lbs 10 mg – 20 mg 4 ml – 8 ml
20 lbs – 30 lbs 20 mg – 30 mg 8 ml – 12 ml
30 lbs – 40 lbs 30 mg – 40 mg 12 ml – 16 ml
40 lbs – 50 lbs 40 mg – 50 mg 16 ml – 20 ml
50 lbs – 60 lbs 50 mg – 60 mg 20 ml – 24 ml
60 lbs – 70 lbs 60 mg – 70 mg 24 ml – 28 ml
70 lbs – 80 lbs 70 mg – 80 mg 28 ml – 32 ml
80 lbs – 90 lbs 80 mg – 90 mg 32 ml – 36 ml
90 lb – 100 lbs 90 mg – 100 mg 32 ml – 36 ml
100 lbs – 110 lbs 100 mg – 110 mg 40 ml – 44 ml
110 lbs – 120 lbs 110 mg – 120 mg 44 ml – 48 ml
120 lbs – 130 lbs 120 mg – 130 mg 48 ml – 52 ml
130 lbs – 140 lbs 130 mg – 140 mg 52 ml – 56 ml


Alternatives To Benadryl

Cannabidiol, or CBD, is a natural, safe, and effective alternative to Benadryl to treat your dog’s allergy symptoms. CBD helps keep your dog’s body in balance, including regulating the systems that fight against allergy symptoms.

This study shows that CBD is an effective treatment for dry and itchy skin, whether from allergic reactions or regular daily allergies. CBD can also help dogs who get car sick by alleviating symptoms associated with motion sickness.

CBD oil tinctures can help treat your pet’s allergies, and you can apply CBD balms directly to your dog’s affected area to help alleviate pain from itchy rashes and dry, irritated skin.

CBD can also help suppress inflammatory responses, which are a common allergy symptom in dogs.

Related: The Golden Dog Treat: Tumeric

How Long Does it Take for Benadryl To Work in Dogs?

In most cases, Benadryl takes anywhere from 30 minutes to an hour to begin working; you should give your dog the correct dose before they are exposed to potential allergens. 

Benadryl can lose effectiveness if you give it to your dog too often, as they build a tolerance to it over time. 

It can take up to 24 hours for the Benadryl to wear off entirely, and the effects can last even longer for dogs with kidney or liver diseases.

Final Thoughts

happy dog

Benadryl is known to be a relatively effective and safe option for treating your dog’s allergies. It’s always a good idea to consult your vet before introducing a new medication to your pet, and you should monitor them closely when giving them Benadryl.

If, like many others, the idea of giving your pet pills from the medicine cabinet doesn’t sound appealing, CBD might be the answer for you and your pets. CBD is an all-natural, effective, and safe way to help your dog get through the allergy season.

Are you thinking about adding CBD into your dog’s routine? Bundle and save now!


Save 20%!

  • Stress and anxiety relieving lick mat and CBD infused peanut butter bundle
  • Perfect for CBD beginners!
  • Provides hours of mental stimulation so your pup will never get bored!
  • Apply with our CBD infused peanut butter Pro tip: Freeze after applying for an extra cool treat and to make it last longer.
  • Includes suction cups for a strong grip on various floors, walls, and during bath time!
  • Dishwasher safe for easy cleanup.
  • Lick Mat Size: 7.25″ X 7.25″ / perfect for dogs of all sizes

Important: The Lick Mat is not a chew toy. Be sure to supervise your dog when using the mat and remove it if it becomes damaged.

Read more

CBD Oil and Soothing Balm Bundle

Bundle And Save 20%


  • Full-Spectrum CBD Oil for dogs and cats, crafted with organic CBD, MCT oil, and chamomile.
  • Third-party lab tested for product safety, potency, and effectiveness.
  • Our all-natural CBD Balm for Dogs & Cats is a daily moisturizer, made to keep your pet’s skin, paws, nose, and elbows soft and hydrated.
  • Third-party lab tested for product safety, potency, and effectiveness.
  • Made in the USA.
Read more

Pet CBD Tincture Trio Bundle (3+ Mix & Match)

Bundle And Save 20%

  • Premium CBD Oil for dogs and cats, crafted with organic CBD, MCT oil, and chamomile.
  • Third-party lab tested for product safety, potency, and effectiveness.
  • Designed to digest seamlessly and deliver rapid relaxation.
  • Available in four concentrations of Full Spectrum CBD: 250mg | For pets under 30 pounds , 500mg | For pets 30 to 90 pounds, 750mg | For pets 90 to 120 pounds, 1000mg | For pets over 120 pound
  • Made in the USA
Read more

CBD for Dogs – Heart + Immunity Bundle

Bundle And Save 20%

  • Full Spectrum CBD Oil in all products
  • All-natural CBD dog treats specially formulated for heart health and immune system support.
  • Premium CBD Oil for dogs and cats, crafted with organic CBD, MCT oil, and chamomile.
  • Our all-natural CBD Balm for Dogs & Cats is a daily moisturizer, made to keep your pet’s skin, paws, nose, and elbows soft and hydrated.
  • Third-party lab tested for product safety, potency, and effectiveness.
Read more
Join Our Waitlist We will inform you when the product arrives in stock. Please leave your valid email address below. WE DO NOT SELL OR SHARE YOUR INFORMATION.
This site uses cookies to offer you a better browsing experience. By browsing this website, you agree to our use of cookies.