Benadryl For Dogs: What, When, and How to Use It - My Blissful Pet

Benadryl For Dogs: What, When, and How to Use It

Allergies strike us all, even our dogs. There are many treatments for dogs' allergies, but one of the most popular is Benadryl. Using Benadryl for dogs can help ease symptoms, and you can get it direct from your local drugstore- or your medicine cabinet.


TL;DR Summary:


A common over-the-counter drug that can be used for humans and dogs to ease allergy symptoms.


Benadryl for dogs can be used when your dog's experiencing allergy symptoms like itchy skin, hives or a runny nose and eyes. It can also combat anxiety and manage vaccine reactions.


The dose of Benadryl for dogs works with their weight. However, getting the right amount and the correct Benadryl to prevent harm to your dog is important.


There are other medications you can use for their allergies and lots of ways to know if they have them.


How to Find Out if Your Dog Has Allergies

Allergies can have a variety of symptoms, they can be chronic or acute, and can be associated with breed type, skin problems or the kind of food that your pup eats. Symptoms can differ subject to the kind of allergy they’re experiencing, but some general symptoms include [1]:

  • Constant licking
  • Itchiness
  • Hives
  • Chronic ear infections
  • Red, inflamed skin
  • Swelling of the Face, Ears, Lips, Eyelids, Earflaps
  • Vomiting
  • Diarrhea
  • Sneezing
  • Itchy, runny eyes
  • Itchy ears

Remember that several of these symptoms can point to other issues so keep a record of what you're noticing and bring it up with your vet. They can also do allergy testing to see if they can determine the cause.

What is Benadryl for Dogs?

You have probably seen or used Benadryl for your own allergic reactions or itchiness. It is a great over-the-counter medication that helps with itching, swelling, sneezing, and other allergic reactions.

The active molecule in Benadryl is called diphenhydramine, and, for the nerds, works by blocking the H1 histamine receptor. This is mostly located in a number of tissues including your lungs and airways, intestine, blood vessels and immune cells. By blocking the H1 receptor, diphenhydramine blocks the effect of histamines on the body. And that’s why when people have allergies, they take “anti-histamine” medicines [2].

This has long made it a staple in human medicine cabinets, but it’s also a great addition to your dog’s medicine repertoire. Benadryl is a popular choice for allergy medicine for dogs because it is so easy to find over the counter and treats a wide range of conditions. [3]

Uses of Benadryl for Dogs


Benadryl has various effects, working on several kinds of canine allergies. This includes food, seasonal, and skin allergies and reactions to triggers like bee stings.


Anxiety affects a huge range of dogs. A study that was published by the University of Helsinki in Scientific Reports revealed that 72.5% of all dogs surveyed showed at least one anxiety-related behavior. [4] Even then, some breeds were more susceptible to it than others such as wheaten terriers or mixed-breed dogs.

With anxiety being such a far-reaching problem, it is unsurprising that vets have a range of recommendations for dealing with anxiety. While fluoxetine is the first choice for vets, Benadryl is often recommended for anxiety because a common side effect is drowsiness, which can help calm anxious dogs. The sedating effect of Benadryl can also be helpful during a stressful vet visit. If you don't have the time to administer a Benadryl before their appointment it can also be given after.

Motion Sickness

The drowsy and sedating effect Benadryl has might be a good option for dogs that experience motion sickness during car or airplane rides.

Vaccine Reactions

Vaccines are an important part of keeping dogs healthy. Puppies especially receive a lot of them early in life, and it is possible to have strong reactions to these early vaccines. Things like fatigue or swelling are common, and Benadryl can be used to combat them.

Veterinarians often say you can give your puppy Benadryl 2 to 4 hours before their vaccination to fight off the reactions immediately.

Side Effects of Using Benadryl for Dogs

While Benadryl is a relatively safe drug, we see some common side effects when we use Benadryl for dogs. Sometimes, these side effects are part of the main reason we're giving the dog Benadryl, such as in dealing with motion sickness or anxiety.

Side effects connected with using Benadryl for dogs include [5]:

  • Rapid breathing
  • Hypersalivation
  • Urinary retention
  • Dry mouth
  • Drowsiness
  • Increased heart rate
  • Rare side effects
  • Diarrhea
  • Vomiting
  • Decreased appetite
  • Increased appetite

Can I Use Normal Benadryl?

You can use this for dogs but it's important to check that it contains only diphenhydramine and it doesn't have other active drugs that can be harmful. For example, some allergy products also contain decongestants which can be dangerous. Products that have xylitol or alcohol can even kill your dog.[6]

Once you've checked the list of ingredient for anything that could be harmful, you can use Benadryl by following the suggested Benadryl for dogs dosages.

dog sleeping between plants no allergies

Benadryl for Dogs Dosage

Getting the right dose of Benadryl for dogs is critical. Giving too much for dog allergies can be toxic, if not lethal, so providing them with the right amount is crucial. That's why it's recommended to discuss it with your vet prior to giving it to your pup.

When it comes to choosing between liquid or tab forms for using Benadryl for dogs, vets recommend using liquid Benadryl for dogs weighing less than 10 pounds because it can make it easier to get the specific and exact dose for their little bodies. However, dogs over 10 pounds can usually tolerate cutting and parsing tablet versions of Benadryl down.

Although recommendations vary, the most common advice for a dose of Benadryl for dogs is 0.9 to 1.8 milligrams per pound of your dog’s body weight 1-2 times a day. [7]

If you’re unsure of how the numbers work out for your dog, you can use one of the Benadryl doses for dogs calculators, such as this calculator from Omni or this calculator from Preventive Vet.

Liquid Benadryl for Dogs Dosage Formula

If you'd like to do the math for providing this to your dog you can use a simple equation. First divide their weight in pounds by 2.5. The result you get is the appropriate dose in milliliters.

For example, say your dog weighs 10 pounds, at 0.9 to 1.8mg/lb body weight he can take between 9 mg and 18 mg of diphenhydramine. Now, 10lb divided by 2.5 tells you that your dog can take 4 ml of liquid Benadryl. The concentration of diphenhydramine in an average bottle of Benadryl is 12.5mg/5ml, this means that your 10lb dog, taking 4 ml of Benadryl will receive 10mg of the active ingredient diphenhydramine. This amount is well in the safe range of Benadryl dose for your dog.

You can measure the dosage with a syringe or teaspoon, where one teaspoon is 5 milliliters.

Identifying a Benadryl Overdose

In the case where you have given your dog Benadryl, watch carefully for any potential signs of overdose. Keeping an eye out for overdose symptoms can help you ensure your dog is safe and that you’re reacting quickly to a potentially dangerous overdose.

Benadryl overdose symptoms include:

  • Rapid heartbeat
  • Dilated pupils
  • Agitation
  • Constipation
  • Seizures

If you spot these symptoms and suspect your dog has accidentally taken too much Benadryl, immediately contact your veterinarian or the closest emergency veterinary hospital. Some dogs can even allergically react to Benadryl itself. So, if your dog starts showing signs of an allergic reaction, take them to a vet immediately.

When Not to Use Benadryl for Dogs

Benadryl is usually very well-tolerated by dogs, but there are some conditions that Benadryl can react poorly with. This is partly why it is so imperative to talk to your vet, to make sure Benadryl isn’t counter-indicated for your dog.

Some situations or conditions where Benadryl should not be used, or should be used under vet supervision, include [8]:

  • Some lung conditions
  • Liver disease
  • Cardiac conditions, including cardiovascular disease
  • Seizure disorders
  • Pregnancy
  • Difficulties urinating
  • Glaucoma
  • In addition to certain medications, such as drugs for treating fungal infections, Cushing disease, or cognitive dysfunction

Other Forms of Allergy Medicine for Dogs

Is There a Dog-Only Benadryl for Dog Allergies?

If you’re nervous about getting the right dose of Benadryl for dogs or aren’t sure about administering human medication to your dog at home, there are other options. There is actually a version of Benadryl for pets that can be used in pets and it’s called Vetadryl.

Some benefits of Vetadryl include:

  • Coming in a 10 mg version to make dosing easier.
  • Coming in dog flavors to make swallowing dog allergy medicine easier.
  • Having completely dog-approved ingredients means you don't have to worry about missing a potentially harmful component.

CBD Oil and Products

CBD oil is a great method of helping humans and dogs with a number of health issues. For example, when it comes to allergies, CBD oil and edible products can help strengthen your dog's immune system so they can better combat allergies. [9] It also helps alleviate allergy discomfort by reducing inflammatory reactions, easing pain*, and making them a little more comfortable.

Dealing With Dog Allergies

It can be pretty scary when your best friend has an allergic reaction. But even when they are sad and sneezy you just want to do everything possible to make it better. So, using Benadryl for dogs to treat dog allergies can help ease the discomfort but it’s not the only way.

For those who favor a more natural route, GiandWin is proud to offer CBD Edibles and CBD Oil specially formulated to release stress and comfort your furry friend. And they taste great, to boot. For more educational tips and tricks on providing a great life for your dog, and to see what CBD treats they will love, you can visit our website.


*These statements have not been evaluated by the FDA, products mentioned here do not intent to diagnose or treat any condition



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