Benadryl for Dogs: The Do’s & Dont’s

Benadryl for Dogs: The Do’s & Dont’s

  • petlycbd Admin - 10.10.2019
Benadryl - What is this popular medicine?

Just like the average human dogs also suffer from allergies and allergic reactions. Allergies can include food allergies, environmental allergies, and flea allergies. Regarding environmental allergies, if something in the air is impacting you, it’s likely also affecting your dog too.

Have dog owners have heard of Benadryl or even taken it themselves? Most likely. It is a popular seasonal medication that helps alleviate seasonal allergies.

Diving into Benadryl science 101, Benadryl is an antihistamine that blocks H1 receptors in smooth muscle and your blood vessels. These H1 receptors, histamine receptors, play a lead role in the allergic response. Benadryl not only blocks this receptor, but also reducblog-tabletates symptoms of these allergic reactions. Benadryl has also been used to provide mild sedation as well as being used to treat motion sickness for dogs.

What would your veterinarian say? Many veterinarians consider Benadryl to have a large safety margin, but there are still potentials for adverse effects and reactions associated with the drug that dog owners should be aware of.

Diphenhydramine? What?

The active ingredient in Benadryl is diphenhydramine HCl. Diphenhydramine has been categorized as a first-generation antihistamine - it can enter and cross the blood-brain barrier to address the allergic response. The blood-brain barrier protects the brain from dangerous or harmful foreign substances, like bacteria or foreign viruses. However, this blood-brain barrier does allow some substances, like diphenhydramine, to pass on through.

Because Diphenhydramine is able to cross the blood-brain barrier, this means that it is typically very effective in treating the allergic response. Diphenhydramine’s ability to cross the blood-brain barrier does, unfortunately, lead to increased risks for potential adverse reactions.


As most dog owners know, because of their own use of Benadryl, the drug is most commonly used to alleviate allergies.

What should you use it for?

Allergies have also been known to range from causing only quick bouts of itching to becoming a chronic, recurring condition throughout a dog’s life, which may lead to other infections and complications.

But - what some individuals may not realize is that Benadryl can be used for several other uses.

Allergies & Benadryl

Starting with the basics here - when we think about allergies, we typically think about a runny nose, constant sneezing, and itchy eyes.

Well, dogs have different symptoms when experience allergies. In most cases, dogs show allergic reactions on their skin’s surface. It is possible that dogs will show signs of allergies that are similar to those you experience yourself, you’ll want to make sure that your pup doesn’t have a more serious issue at hand.

If your dog is having nasal discharge, coughing, and inflamed eyes, this can be a sign of multiple conditions in dogs, especially respiratory infections. So, it’s important not to automatically assume that your pup’s symptoms are from allergies.

Bottom line - your dog can suffer from allergies & your vet may recommend Benadryl to help alleviate your dog’s symptoms.

Benefits of Apoquel for Dogs

The most appealing part of Apoquel for dogs is how quickly it begins to work.

Dog allergies include:

  • Seasonal allergies
  • Environmental allergies
  • Food/drink allergies
  • Insect bite allergic reactions

Unfortunately, we aren’t exactly able to communicate with our dogs in a clear way, despite how badly we wish we could. Our dogs can’t let us know when something in the air is bugging them, or if their food has ingredients they don’t like, or if any of this is making them feel funny. We can’t describe to them how badly insect bites feel and ask them to please avoid those fun, innocent-looking bugs are in the grass.

For this reason, knowing that Benadryl is safe to give to dogs, makes many dog owners feel somewhat at ease if their fun-loving pup is prone to being in grassy, itchy situations. With this being said, we want to emphasize, as in humans, allergies and other various conditions can be mistaken or mistreated for one another. Taking your pup to see the vet will give assurance in determining whether or not your dog has a skin infection/condition or an allergic reaction.

When to Call the Vet - Allergies 101

Many veterinarians and pet owners find Benadryl to be a highly effective antihistamine for mild to moderate allergic reactions.

However, if your dog is having an acute allergic reaction with difficulty breathing or face swelling, it is extremely important that you go directly to the vet.

Benadryl is not effective in serious cases of allergies. Seeking medical treatment and intervention in a timely manner is crucial for your dog’s life if he/she is having allergies.

What Dose of Benadryl

Benadryl is typically administered in tablet form when prescribed for dogs. However, liquid Benadryl can be mixed what your dog’s food, only if your vet confirms this is safe to do so. Consult with your vet first!

Benadryl dosage is based on your doggo’s body weight. Below, we’ve included a general guide for ging your dog Benadryl.

For dog owners who want an accurate dose, experts say that 1 milligram (mg) of Benadryl per pound of body weight is the most accurate way to calculate the amount of Benadryl that will be safe, effective, and appropriate for your dog.

How Much Do I Give My Doggo?


Weight of Dog

30 lbs or less 10 mg per dose
30 - 50 lbs 25 mg per dose
50 lbs or greater 50 mg per dose

You can typically give this medication to your dog is around 2 -3 times per day, at least 8 hours apart between doses. Benadryl takes typically 30 minutes after administration to come into effect. Not all dogs are the same - all dogs respond differently to new medication. Therefore, it is extremely important to talk to your vet about the dose that is ideal and right for your particular doggo.

But is Benadryl Safe For My Pup?

Benadryl has been deemed safe for dog use when used appropriately, but there are a few things to be aware of as a dog owner.

When to Avoid It

Doggos with glaucoma, cardiovascular disease, heart conditions, and high blood pressure should avoid Benadryl, as it can worsen their condition. Furthermore, dogs with the following conditions should avoid receiving Benadryl:

  • Allergic lung diseases
  • Heart failure
  • Angle-closure glaucoma
  • Pregnancy
  • Nursing
  • Hyperthyroidism
  • Seizures

Side Effects of Benadryl

  • Increased heart rate
  • Fast breathing
  • Urinary retention
  • Dry Mouth

(Most Uncommon) Side Effects of Benadryl

  • Decreased/increased appetite
  • Vomit
  • Diarrhea

Get Hives?

Benadryl has also been known to effectively treat hives in both humans and doggos. In dogs, most of the time, hives are simply due to allergic reactions.

In humans, hives can be symptoms of several underlying medical conditions, so treating them with Benadryl may work for immediate relief, but not as a long-term treatment and will certainly not cure it.

Pets will hives may look pretty sad and miserable, we want to encourage pet owners not to panic if your pup breaks out in hives. These hives can be treated, typically without any issues or complications.


One major side effect of diphenhydramine, the leading active ingredient in Benadryl, is drowsiness. If your pup has anxiety, your vet may prescribe Benadyrl to help ease symptoms of anxiety and help effectively calm your anxious guy/girl down.

Motion Sickness

Pet owners may not know that Benadryl is recommended for dogs who often experience motion sickness in the car.

Treating Cells with Benadryl?

Mast cells are white blood cells that play a role in allergies. When your dog has mast cell tumors, this leads to mast cell degranulation. This causes a massive histamine release, aka, an allergic reaction.

If your dog has a mast cell tumor, your vet may recommend Benadryl to alleviate and reduce symptoms from the histamine release from the mast tumor cells.

Heartworm Treatment & Benadryl

When adult heartworms are present, heartworm treatment kills these adult heartworms. The death of these heartworms can trigger and lead to a serious allergic reaction for your pup. If your pet has to undergo heartworm treatment, it is common that your vet may recommend Benadryl to ease the symptoms associated with the heartworm treatment.

When to Call the Vet - Allergies 101

Many veterinarians and pet owners find Benadryl to be a highly effective antihistamine for mild to moderate allergic reactions.

However, if your dog is having an acute allergic reaction with difficulty breathing or face swelling, it is extremely important that you go directly to the vet.

Benadryl is not effective in serious cases of allergies. Seeking medical treatment and intervention in a timely manner is crucial for your dog’s life if he/she is having allergies.

Benadryl Overdose

Benadryl can cause hyperexcitability of your dog’s central nervous system. It is critical to seek proper medical attention if your dog may be experiencing an overdose.

Overdose signs include:

  • Seizures
  • Rapid heart rate
  • Irregular heartbeat
  • Confusion
  • Constipation
  • Muscle tremors

Home Remedies for Dog Allergies

As a pet owner, you got options! Luckily, there are some extremely effective and safe alternatives to Benadryl that may support skin health. Alternatives down below come with virtually no side effects. Peep below!

Oatmeal Bath

An oatmeal bath can serve as a soothing home remedy for your pup’s irritated and itchy skin, given that your dog isn’t allergic to oatmeal (which would be horrible, let’s be honest). Step one, mix plain oatmeal with water and apply it to your dog’s irritated skin. Step one in a half, or you can run a bath and add oatmeal directly to the water. Let your pup soak for 10 minutes to put their scratchy, itchy skin at ease.

Coconut Oil

You can totally give your pup coconut oil to soothe any irritation and even prevent parasites. Key tip - look for coconut oil that is high in lauric acid, this makes the coconut oil more effective. Apply a small amount directly to your dog’s skin or feed it to them. Feed them a small amount (¼ teaspoon for small pups, 1 teaspoon - 1 tablespoon for large pups) 1 - 2 times a day with their meals.

CBD Dog Treats

You can also use our 3 mg of broad spectrum hemp CBD. We recommend our PETLYcbd natural beef flavor CBD pet chews. These treats include grain free, preservative free, and non GMO, organically grown hemp that supports healthy skin and a smooth, healthy coat. These scrumptious, yummy mouth treats are definitely a paw favorite.

The Benadryl Take-Home Message

We understand how stressful it can be - shuffling through endless lists of medications and drug options, figuring out what’s safe, which option has the least amount of side effects, and what has the least potential for adverse reactions. STRESSFUL. Medications like Benadryl may be “safe” for short-term treatment, yes, it is comforting to know it’s not your only solution. We encourage our readers to explore all-natural, organic options like CBD.

Your doggo will definitely thank you!

Leave a comment