Zyrtec for Dogs: What to Know

Zyrtec for Dogs: What to Know

  • Kirsten Thornhill - 11.03.2020

Allergies can be no fun, you will likely have to deal with them at some point in your life to some degree, if you haven’t already. It may be of a shock to paw parents that those common symptoms associated with allergies such as irritated and dry skin, sneezing, and itchy-eyes affect our four-legged fur babies too. 

While allergies may show in different ways, allergies can affect our pups just as much as they can affect us humans. Ruff. Unfortunately, our dogs aren’t exactly able to communicate with us humans about what’s really going on. 

So as a loving paw parent, what can you do? What do you do to help?



If you’re more prone to developing allergies when the seasons change then you’ve likely heard of common over-the-counter (OTC) antihistamines, such as Zyrtec. 

A conventional medication, like Zyrtec for instance, is just one of the second-generation antihistamines, meaning that it is often prescribed for us humans who are coping with environmental changes that often present us with runny noses and red, itchy eyes. 

Zyrtec does not cause any drowsiness like other antihistamines (like Benadryl for example).

The FDA has not yet approved the use of Zyrtec for animals, however, more and more veterinarians are prescribing for dogs to help reduce allergic reactions and itching.



Cetirizine is an antihistamine and is the main active ingredient in Zyrtec. It’s also seen in other allergy medications including PediaCare Children’s 24-Hour Allergy, Aller-Tec, Zyrtec Allergy, Children’s Zyrtec Allergy, and Children’s Zyrtec Hives Relief. 

Cetirizine works by blocking the body-producing natural histamine when you are experiencing an allergic reaction. 

Since Cetirizine blocks histamine, it’s included in the class of medications known as antihistamines. 


Can My Dog Have Zyrtec


If your pup is affected by allergies, your vet may recommend Zyrtec.


These allergic reactions are typically seen and associated with atopic dermatitis as well as contact dermatitis. 

Both of these dermatitis can trigger allergic reactions including swelling, itching, hives, and or inflammation. 


Allergy Signs in Dogs

Just like us humans, dogs can be allergic to almost anything you can imagine too. In addition, certain allergens can have a greater effect and impact on dogs than other allergens. 

Often times, we think of allergies being a runny nose and watery, itchy eyes. However, dogs may show allergy symptoms in different ways too.

If your doggo is prone to getting allergies or is having an allergic reaction to something, you may see some of the following symptoms:


  • Swelling
  • Excessive itching
  • Rubbing of the face
  • Biting their paws or legs
  • Skin redness
  • Skin irritation


If your dog’s allergies are left untreated, it may result in hair loss and or skin infections, including yeast infections and bacterial infections. Not to mention, they may even develop hot spots. 

If your pup is having a severe allergic reaction, they may develop hives and possible anaphylactic shock (in extreme cases). 

Signs of anaphylactic shock are sudden onset of diarrhea, excessive drooling, seizures, coma, and even death. If you’re able to look at your dog’s gums, they may be more paler than usual, instead of a healthy pinkish color. Instead of their normal worm limbs, they may feel cold. Your vet will also be able to detect any heart abnormalities in their heart rate and pulse.

If you believe your dog may be going into anaphylactic shock, it’s crucial that you seek vet assistance right away, as it can be life-threatening. 


Dog Allergies: The Causes

 Commonly seen, allergies in dogs can be triggered by fleas, more specifically from the saliva from fleas and flea bites. Environment allergens such as grass, pollen, dust mites, and weeds can be an allergy culprit too. Lastly, food allergies are common for dogs including the food they eat themselves, but also food additives.


Dosage for Dogs: Zyrtec

In general, the appropriate dose of Zyrtec for dogs is typically determined by their size. Your vet may prescribe Zyrtec to be given orally, once a day.

However, as a general rule of thumb, this isn’t what you should do for your pup persay. Because this isn’t an exact science rule that works every time, it’s important that you see your vet to determine an accurate dosage for your personalized puppers. 


The dosage of Zyrtec may vary - based on what your pup needs treating for. For example, the dosage to treat itchy skin may be different from the dosage needed to treat an allergic reaction. 


What Paw Parents Should Know About Zyrtec-D

The most important thing you can take away from this article:

never, ever, EVER use Zyrtec-D


Zyrtec-D contains an active ingredient called pseudoephedrine, which can be extremely harmful to dogs, even with potential cause of high blood pressure, seizures, and possible death. 

Generic Zyrtec and standard Zyrtec contain the active ingredient cetirizine, which vets have deemed safe when given appropriately. 

Side Effects of Zyrtec

Zyrtec doesn’t typically present many potential side effects that are too worrisome for paw parents, especially if you are familiar with potential adverse reactions of other various conventional medications. 

Don’t be worry-free quite yet, there is still some concern associated with Zyrtec use in dogs. Experts claim that antihistamines are only in approximately 30% of dogs (maybe even less). The worst part? Up to 25% of dogs may experience side effects. 

In addition, antihistamines are not the cure, more so they are like a band-aid, only providing temporary relief. The antihistamine may treat the signs and symptoms, yes, but they will not cure the root of the problem. There may be something severe behind those seasonal allergy symptoms.

Okay, okay, now onto the bullet point side effects of Zyrtec. The most common adverse side effect of Zyrtec is sleepiness.



  • Urine retention
  • Vomiting
  • Constipation
  • Excessive salivation
  • Impulsive behaviors



Zyrtec can cause more issues for dogs that have kidney and or liver issues.

While your pup may no longer have signs and symptoms of those seasonal allergies, it is possible that Zyrtec may make other issues worse. 


Some Precautions for Zyrtec

As we mentioned above, one of the potential adverse reactions of Zyrtec is urine retention. This can give light to some serious problems in doggos with kidney issues. 

The same potential harm applies to dogs with liver problems. Zyrtec can lead to further liver issues and make your dog’s current situation much, much worse. 

To this day, there still aren’t enough studies to determine whether or not the drug is completely safe for pregnant dogs. Because of this, we advise paw parents to stay away from Zyrtec is your pup is pregnant. 

Make sure your vet is aware of any other medications you’ve been giving to your pup. Whether you want your pup to start Zyrtec or any other medication, it’s important your vet knows exactly what your dog is taking at all times. So your vet can prescribe a drug that is most likely to have less potential side effects when mixed with fido’s other current medications. 


At-Home Allergy Remedies for Your Dog

Luckily, as a paw parent, you’ve got options! There are some effective and safe alternatives to Zyrtec that help support your dog’s skin health amongst other issues.

The good news? The options we’ve about to discuss come with virtually NO SIDE EFFECTS. 


Coconut Oil

Yep, you can give your dog coconut oil to sooth irritation and even help prevent parasites. Grool. Make sure and look for coconut oil that is high in lauric acid, making it more effective. To use coconut oil, just apply a small amount to your pup’s coat or simply feed it to them for snack!

If you choose to use coconut oil as a snack, start with a small amount (¼ teaspoon for small pups and 1 teaspoon for larger pups), 1 - 2 times a day. 


Oatmeal Bath

Oatmeal can serve as a soothing tool for irritated and itchy skin, for you and your pup! Just add water to the oatmeal and apply it to their irritated skin. Or, you can always fill up the tub and pour the oatmeal into the water. 

Give your pup about 10 minutes worth of soaking in the oatmeal mixture to relieve that itchy skin. 



You can also use pure, hemp CBD Oil. Studies have suggested that CBD oil supports skin and joint health, especially in animals with sensitive skin. 


PETLYcbd broad-spectrum hemp CBD Oil is all-natural, non-GMO, lab-tested, THC-free, vegan, gluten-free, and veterinarian approved. We offer three levels of CBD oil, based on your dog’s size and weight, to ensure that your pup gets the right amount of CBD to support canine health. 

CBD oil can be dropped directly onto your pup’s tongue, mixed into their food, or baked into their favorite treats!

CBD Dog Treats

Or, if you’re not a master baker in the kitchen, we have CBD dog treats available for you! We recommend our CBD Pet Chews. These strain specific treats include a water soluble broad-spectrum CBD that is 5 - 10 times more bioavailable than other oil based treats.   



These yummy natural beef flavored treats are definitely a paw favorite. 

Zyrtec: Final Thoughts

When all is said and done, we know you want what’s best for your pup. 

Zyrtec may be deemed safe for dogs with an appropriate dose. However, being safe over sorry may apply here. As a paw parents, always consult your vet prior to giving your pup any new medication. Also, do your research about the new potential medication, so you can learn about the potential side effects. 

When all is said and done, allergies are the worst. It is comforting knowing that there are conventional and all-natural options available for your pup. 

Hang in there pup, relief is on the way!

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