Are Antihistamines For Dogs Safe?

NOTE: You should always contact your veterinarian for advice and guidance before giving a pet any over the counter medication

No dog owner likes to see their pup sneezing, coughing and irritated due to an allergy. Yet finding a solution to the problem seems to be a lot harder than it should be.

Effective, safe and dog-specific allergy medicines seem to be annoyingly difficult to get your hands on (although they do exist), and so it’s only natural that dog owners have begun to question whether our own human antihistamines could help alleviate the symptoms of a struggling four-legged friend.

From Benadryl to Piriton, this article will explore the pros and cons of giving your dog human antihistamines, helping you to put a stop to your animal’s agitation!

Can I give my dog human antihistamines?

Human antihistamines are usually safe for dogs to take, but make sure you check the brand and correct dosage amount with your vet before giving one to your pet.

The most commonly used antihistamines are diphenhydramine, cetirizine and loratadine, which can all help relieve symptoms such as itching and sneezing for dogs.

antihistamines suitable for dogs

Although sounding decidedly scientific, you may know these better as the main ingredients in well known branded allergy drugs such as Benadryl (diphenhydramine), Claritin (loratadine) and Zyrtec (cetirizine).

Just like with humans, these antihistamines can sometimes have side effects on dogs and so you need to be wary. Thankfully these aren’t usually harmful and tend to result in either making a dog very drowsy or opposingly making them behave more hyperactive or erratically.

But although most brands are generally safe, you do need to be careful when shopping for over the counter antihistamines. Occasionally they will contain other harmful ingredients such as decongestants which could be toxic for your dog.

Such mistakes can be avoided by thoroughly observing the label and ingredients list, or by getting in touch with your vet!

Best antihistamine for dogs

The best antihistamine for dogs is the Vets Best Seasonal Allergy Tablet, purely because it’s one of the only antihistamines on the market to be made especially for canines and not humans.

In fact, it’s not even suitable for human consumption!

This means you no longer have to stress over whether you can give your pooch a Piriton or not, as there’s already a doggy designed option readily available!

While most canine allergy relief products are merely a vitamin or fatty acid supplement designed to boost itchy skin, Vet Best’s tablets are one of the few to contain an actual antihistamine that prevents your pup’s body from reacting to allergens and stimuli they are sensitive to.

The tablets utilise the active ingredient diphenhydramine hydrochloride, the same antihistamine used in popular human allergy tablets such as Benadryl. And unlike other dog allergy medicines like Apoquel, Vet’s Best doesn’t require a prescription, making them a cheaper and less time-consuming, quick fix!

The tablets work in the same way as a human drug, by blocking the body’s H-1 receptors in the blood vessels and muscles. This prevents your dog’s body from producing histamines when confronted with non-harmful allergens, and in turn prevents irritating reactions like itching, sneezing, watery eyes and a runny nose.

what is the best antihistamine for dogs

Anyone who owns an allergy-suffering pup knows that skin issues are often the most troublesome symptom. So Vet’s Best tablets are a particular lifesaver when it comes to providing fast relief to minor skin irritations, helping to reduce constant scratching.

As the tablet is designed for dogs, working out the right dosage for your pet pooch is also totally hassle-free. Here is the simple dosage table for you to follow, based entirely on your pup’s weight!

  • 10-24 lbs: 1/2 tablet
  • 25-49 lbs: 1 tablet
  • 50-75 lbs: 1 1/2 tablets
  • 75 lbs+: 2 tablets

As with any medicines, you should always check with your vet before administering Vet’s Best to your pet, just to be safe.

Ask a veterinarian before use if your pet has:

  • Glaucoma
  • Asthma
  • Heart Disease
  • Hypertension
  • Urinary Bladder Obstruction
  • Enlarged Prostate Gland
  • Hyperthyroidism
  • Is Pregnant or Nursing
  • Weighs under 15 lbs

It’s also particularly important to avoid using it in combination with any other product which contains diphenhydramine, to help avoid overdose

Can I give my dog Benadryl?

Although it might seem strange, it is usually safe to give your dog Benadryl to relieve allergy symptoms, and it’s even prescribed or recommended by some vets.

However, like with any drug, it may not particularly be the best solution to your pup’s problem!

Benadryl has been known to have adverse effects when taken in combination with other medications your dog may be on, which is why it’s always imperative to talk to your vet before administering it.

How and when to use Benadryl for dog allergies

Benadryl is best for dogs who are suffering from low to mild allergic symptoms because the drug isn’t specifically formulated for canines, so their effectiveness can range from mild to effective.

is benadryl ok for dogs

However, vets still often use it to ease environmental allergies in pups and also to deal with reactions to insect bites or stings. It can also be used as a pre-treatment for possible vaccine reactions.

It is to be taken orally, so it is often easiest to add a pill to your dog’s food.

Benadryl is not a suitable medication if your pet is having an acute allergic reaction.

Symptoms of an acute reaction are characterised by facial swellings, difficulty breathing and in rare cases anaphylactic shock.

When to avoid Benadryl

Benadryl is one of the safest over-the-counter drugs that can double up as a doggy medication.

However, for canines with certain health issues, they are not the smartest choice.

For pregnant dogs, dogs with glaucoma and canines with low blood pressure or cardiac conditions, taking Benadryl is an unneeded safety risk and so it’s best to avoid using it.

And it’s also important to note that if you make the wrong choice, they can be a risk for healthy dogs too. That’s because some Benadryl tablets are combined with other medicines which make them unsuitable and so it’s vital you ensure your Benadryl tablets contain only diphenhydramine.

What’s the correct Benadryl dosage for a dog?

The recommended dosage of Benadryl for a dog is 1 mg per pound of body weight, to be taken 2-3 times a day. Standard tablets are 25 mg, and so they are the perfect size for a 25 lbs dog.

Obviously this gets trickier when your pup is slightly larger or smaller than 25 lbs and so the most reliable thing to do is ask your veterinarian for the correct dosage for your canine.

Can I give my dog Piriton?

It is generally considered safe to give a dog Piriton to treat environmental allergies, as long as you have sought guidance from a veterinary professional first.

Unlike some of the previously mentioned antihistamines, Piriton is mainly made up of the ingredient chlorphenamine. In the human world, this drug is mainly used to treat runny, itchy noses and hive symptoms, making it a great anti-allergy tablet.

However similar to Benadryl, it is often prescribed by vets to help treat dogs suffering allergic reactions.

is piriton ok for dogs

But as with Benadryl, if using Piriton for a pup, you should be wary of there being a chance of side effects.

In Piriton these can include; drowsiness, constipation, dry mouth and nausea. In rare instances, these can be more severe and may include respiratory issues, irritability, poor coordination, urination issues and affected concentration.

Thankfully, all of these reactions tend to be fairly mild if they actually occur.

When to avoid Piriton for dogs

If your dog has an existing medical condition, it isn’t worth taking the risk and giving them Piriton without the advice of a vet.

What’s the correct Piriton dosage for a dog?

Typically, vets recommend dosing by the dog’s weight at 0.9–1.7 mg per pound of body weight, every 8 to 12 hours.

It’s important to remember though that this is merely a guideline, and as always, the best way to determine the correct dosage for your dog is to contact your vet.