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Children’s Benadryl for Dogs

Medically reviewed by Paula Simons, DVM

There’s nothing a dog parent hates to see more than their dog scratching themselves until they bleed.

Dog owners all over the world seek to find the best way to reduce symptoms of dog allergies. Altered diets, medicated creams and prescription medications are often chosen in desperation.

The correct Benadryl dosage for dogs primarily depends on the dog’s size (weight).

It’s important to also consider other underlying health conditions and whether Benadryl is the appropriate choice overall. Ultimately, a veterinarian is your best source of advice.

Does Your Dog Have Allergies?

Dog allergies include everything from runny nose and sneezing to a relentless itch that becomes painful over time.

The best use of over-the-counter Benadryl is for dogs with mild allergies or bug bites. It can be a temporary solution but should not be used long term.

When in doubt, give your veterinarian a call and ask how much to give the medication and how often.

The Appropriate Benadryl Dosage for Dogs

The appropriate dosage for dogs depend on their weight. Follow the formula below for best results.


Please make sure that the Benadryl used is either a tablet or capsule.

The liquid form contains ingredients that can be harmful to your dog. Make sure there is no alcohol, acetaminophen, pseudoephedrine, or artificial sweeteners in any product or food you give your dog.

Xylitol is extremely toxic for dogs.

Benadryl Dosage Formula for Dogs

The generally accepted rule is to administer 1 mg per pound, two to three times a day.

It’s best to space apart the dosages through the day. For example, offer a dose in the morning, late afternoon, and before bedtime if necessary.

However, that can vary slightly depending on the actual size of your dog. Unless you’re absolutely sure of your dog’s recent weight, you may want to find someone with a large, walk-on scale similar to the kind found at the vet’s office.

Children’s Benadryl for dogs is administered based on weight

At-Home Scales Are Tricky

Using an at-home scale might be tricky and not as accurate. Many veterinarians will allow you to bring your dog in for a quick weigh without charging the fee of a full visit.

Based on the assumption that you know your dog’s recent weight, you can use the following guide to help determine the best Benadryl dosage for dogs.

Very Small Dogs (4 – 10 pounds)

Very small dogs within the 4 – 10 pound range would need 1/4 of a Benadryl tablet (regular strength).

Small Dogs (10 – 20 pounds)

Small dogs in the 10 – 20 pound range would need 1/2 of a Benadryl tablet (regular dose).

Medium Dogs (20 – 30 pounds)

A medium dog would take 1 Benadryl tablet.

Large Dogs (30 pounds and over)

The dosage rules change a little when we get to very large dogs. Types of very large dogs include:

  • Great Dane
  • Mastiff
  • Newfoundland
  • St. Bernard
  • Great Pyrenees.

If your dog is right at the 30 pound mark (a little lower or a little higher), a 25 mg Benadryl tablet should suffice.

Benadryl comes in 25 mg and 50 mg tablets.

Alternatives to Benadryl for Dogs with Allergies

There are many medications designed to promote dog health and immune support. In addition to veterinarian prescribed options, you might want try an alternative.

Consider A Raw Food Diet

Have you thought of switching your dog to a raw food diet. In some cases, pet parents have reported relief for their pets after changing their pup’s diet.

It’s important to start slowly when changing your dog’s diet before making the complete switch. There are tons of raw food dog diet companies out there. It’s hard to know where to turn. We’ve included a few of our favourites in this post to get you started:

Please note that the following are affiliate links. That means if you decide to purchase something after clicking a link, I may earn a small commission. This does not cost anything more to you.

Raw Wild (Wild sourced raw dog food)

Raw Wild offers premium dog food with no GMO’s. It’s gluten-free, grain-free, and comes with a healthy mix of veterinarian approved vitamins and minerals to ensure your dog gets a balanced diet.

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Darwin’s Natural Pet Products

Darwin’s offers fresh, raw pet food for dogs and cats along with free home delivery.

Choose from Natural Selections (premium recipe made with the highest-quality free-range meats and organic vegetables or BioLogics, their value recipe using the same complete and balanced formula.

Their website makes it easy to determine where to start including a quick questionnaire to gently point you in the right direction.

Click the link below to check out Darwin’s Natural Pet Products.


Quercertin is a bioflavonoid dubbed “nature’s Benadryl”. This is because it’s thought to have a similar response in the body.

This supplement is said to reduce the histamine response due to allergies in dogs.

Follow dosing instructions on the box and be sure to tell your veterinarian about any new supplements you are giving your dog. “Natural” products can still have unintended consequences.


Magnesium is thought to reduce inflammation caused by allergies in dogs. It has other supplemental benefits beyond inflammation including (and suggested by some holistic practitioners) to reduce anxiety in dogs.


There are many blogs and anecdotal posts about the benefits of cbd oil for dogs with allergies.

Scientific studies are difficult to find although it seems that CBD oil does show promise in treating dogs with allergies and anxiety.

The most important thing to look for is the absence of THC in whatever product you use. Follow dosing instructions. If you have access to a holistic veterinarian, talk to them about CBD oil for dogs.

Side-Effects of Benadryl in Dogs of All Sizes

Benadryl is safe for dogs. If side-effects are experienced, they are typically mild and include drowsiness, low energy, dry mouth, and urinary retention.

Benadryl is the brand name for the active ingredient known as Diphenhydramine and is a medication that soothes allergic reactions in dogs and people.

In the rare occurrence where your dog experiences severe side effects, including difficulty breathing, seek veterinarian/medical assistance right away.

Likewise, Benadryl is not to be given to dogs who are already experiencing difficulty breathing.

How to Administer Benadryl to Dogs

Pet stores sell various types of treats that come with a hole in which to place the tablet.  Dogs are usually so happy to get treats they’ll just gobble it up in seconds without even noticing the pill.  

Benadryl Capsules 

If you are using Benadryl capsules, break one open and sprinkle it on the dog’s food, mix it with a teaspoon of peanut butter, or sprinkle on a piece of toast.  

While Benadryl is FDA approved for people, it’s not specifically designed for use in dogs. For that reason, liquid Benadryl and other formulations may contain potentially harmful ingredients.

Make sure to read the label and avoid ingredients like alcohol, xylitol, etc.

Side Effects of Benadryl You Should Know

Benadryl works fast to treat allergy symptoms like itching. Occasionally, mild side effects can occur. These include dry mouth, fatigue, rapid breathing, and urinary retention. 

If you’re sticking with the Benadryl dosage chart, however, most healthy dogs will not show any serious side effects. 

You might also be interested in Putting a Dog to Sleep with Benadryl.

Disease versus Benadryl for Dogs 

Never assume that that Benadryl dosage chart is right for all dogs. In fact, your veterinarian may have very good reasons for not recommending the medicine at all. 

If your dog has any kind of chronic condition (diabetes, Cushing’s, allergies that lead to secondary bacterial infections, glaucoma, etc.) ask your veterinarian if Benadryl is appropriate.

If your dog hasn’t been to see the veterinarian for a while, he/she may suggest a visit. 

The reason for this is so that the dog can be examined for underlying conditions. A physical exam along with regular yearly blood work can go a long way in making sure your dog stays healthy.

There’s a chance that your dog needs more than just Benadryl, or that the problem you thought you were treating wasn’t actually the whole picture.

Benadryl for dogs can alleviate itching


Just because you gave your dog Benadryl safely a few years ago, doesn’t mean it’s safe now.  Remember, your dog’s health may have changed and he/she could have underlying conditions you are not aware of.

Look at the product ingredients to be sure it only contains diphenhydramine. Some Benadryl products have added ingredients.

Benadryl should not be given to your dog long-term. If your dog continues to suffer with an itch or has symptoms of allergies that get worse, bring him/her to the veterinarian. 

Aggressive itching and biting at the area can cause a bacterial infection. It may even indicate that the problem isn’t allergies at all. One example is when a dog gets an anal abscess.

This can happen when the anal glands don’t empty properly during regular bowel movements.

Over time, those sacs (they are located just inside the dog’s anus at ”5 o’clock” and ”7 o’clock” if you imagine you’re looking at a clock.

Learn more about anal gland abscesses in dogs:

Anal Gland Abscess in Dogs

At the end of the day, everyone wants a happy and healthy dog. 

Remember that you’re not alone when it comes to health-care decision making. Always check with a licensed veterinarian before administering over-the-counter drugs designed for people or pets. The appropriate Benadryl dosage for dogs may vary according to special health considerations.  

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