Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Zyrtec for Cats: Dosage, Uses & Side Effects (Vet Answer)

Share

white pills tablets

Allergies in cats can sometimes have the same symptoms as us – watery eyes and nose, mild congestion, and sometimes coughing. More frequently, allergies in cats will manifest as itchy skin, redness, and/or swelling of the skin.

The brand name Zyrtec may sound familiar to you. It’s a common over-the-counter (OTC) allergy medication that many of us have taken in the midst of pollen season. But can cats take Zyrtec? Yes, Zyrtec can be given to cats, but it’s important to consult your veterinarian before giving Zyrtec to your cat. In this article we’ll discuss what Zyrtec is, if and how you can give it to your cat, and potential side effects that your cat may experience.

divider cats oct 2024

What Is Zyrtec?

Zyrtec is the brand name for the drug Cetirizine HCL (Cetirizine Hydrochloride). Zyrtec is an antihistamine allergy medication. When your cat’s body reacts to an irritant and/or an allergen, the body will release histamine. This is a natural substance that occurs and can be released with no problems. With allergies and/or an allergic reaction, excessive histamine can cause itching, redness, and sometimes swelling. Antihistamines work by blocking histamine from attaching to certain cell receptors that then cause the effects listed above. Zyrtec is in the class of antihistamines that are classified as an H-1 blocker.

woman-giving-pill-to-cat
Image Credit: New Africa, Shutterstock

How Is Zyrtec Given to Cats?

Zyrtec is given orally. If your veterinarian recommends you give the OTC product, it comes as a tablet, chewable tablet, gelcap, or a children’s formula liquid. The gelcap will likely not be recommended due to the dosing your cat needs. If your cat is difficult to give medication to, your veterinarian may also have the medication compounded. This means that a compounding pharmacy will make the medication into different forms than what is available OTC and can also make it flavored.

Zyrtec can be given to cats every 12–24 hours, or once to twice a day. It does not have to be given with food, though giving a cat medication can be extremely difficult. Sometimes giving it in food can be much easier as your cat may eat it more easily in a snack such as tuna. Giving Zyrtec with or without food will not alter its effectiveness.

divider 3 paws

Zyrtec Dosage for Cats

So how much Zyrtec should you give your cat? First, It’s important that you know their current weight. Depending on the weight of your cat, the dosing for Cetirizine is 1 mg of Zyrtec per 1 kilogram of your cat’s body weight. Typically, this will be 2.5 mg to 5 mg total. However, make sure to check this with your veterinarian as they may recommend a different dose.

What Happens If You Miss a Dose?

The best part is that there are no serious side effects if a dose is not given, or if your cat just won’t allow you to give them the medication. Zyrtec is not a medication that has to be weaned up or down in order to be effective for your cat.

It’s worth noting that significant allergies in cats are often not affected by OTC antihistamine products. In other words, you will not notice any improvement in the allergy symptoms if your cat has significant allergies. If you are regularly giving your cat the recommended dose of Zyrtec, and both you and your veterinarian are not noticing an improvement in their allergy signs, it may not work for them. At that time, you should discuss other options with your veterinarian.

Potential Zyrtec Side Effects in Cats

In general, cats can be very stubborn and dramatic when getting any medication. Zyrtec does not have any common side effects, but some cats will spit, drool, foam at the mouth, and be dramatic simply because they are being medicated.

Mild drowsiness is possible, especially with smaller cats, but does not always occur.

If your cat has underlying liver and/or kidney disease, your veterinarian may recommend a lower dose and/or a less frequent dose. This is because it may take your cat longer to process the medication if they have the existing conditions.

woman brought her maine coon cat to the vet
Image Credit: Gorodenkoff, Shutterstock

divider cat paws 2 oct 2024

Frequently Asked Questions (FAQ)

Can I Give My Cat Zyrtec D?

No! This can be extremely harmful and potentially deadly for your cat. The “D” in the name stands for decongestion, and this formula contains the drug pseudoephedrine. Pseudoephedrine can be extremely harmful to dogs and cats, and can be highly fatal. Never give your cat or dog any medication containing pseudoephedrine unless explicitly prescribed by your veterinarian.

Is Zyrtec Effective?

Zyrtec can be effective for mild pruritus (itchiness) in your cat. However, for severe underlying allergies, OTC medications are often not enough. Your cat may need a new diet, appropriate flea preventative, prescription allergy medications, or steroids to completely stop itching.

divider cat faces oct 2024

Conclusion

Allergies in cats are most frequently seen as itching skin. Over-the-counter antihistamines can sometimes be helpful in relieving some of the most common symptoms of allergies. Zyrtec is one of these common OTC medications that can be given. It comes in oral form and should be dosed based on your cat’s current weight and your veterinarian’s recommendations based on that weight.

Zyrtec is given as an oral medication either in tablet or liquid form, or your veterinarian may have a compounding pharmacy make the medication into a different form. There are very few side effects aside from occasional drowsiness. It’s important that you never give your cat Zyrtec-D, and you are aware that any OTC antihistamine may not be effective. Always work with your veterinarian for their best recommendations.


Featured Image Credit: Purricious, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.




How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.


Catster's Digital Magazine is Back!

Vet-approved health & behavior advice

Real cat stories & community features

Chatting About Big Cat Tourism, Lion Hunting, and Learning From Our Mistakes | Chatty Cattys, Episode 26

In this episode of Catster’s Chatty Cattys podcast, Nicole and Dr. Karyn dive into the dark side of big cat tourism and the...

Why Cats Sit by the Door (But Don’t Go Through It)

Door-sitting is one of those quirky little habits that almost every cat owner experiences at some point. You know how it goes: a...

Six Legs Are Better Than Three – How A Tripod Dog and Kitten Found Friendship Through Recovery

Sometimes the most meaningful friendships begin in the most unexpected places. At a Maryland veterinary hospital operated by Last Chance Animal Rescue, two...

The Original Space Invaders – Why Zero Respect for Personal Boundaries Is a Good Thing

Cats have a reputation for being independent, and in many ways they are. But anyone who has tried to work at a laptop...

More related

Orange Munchkin Cat: Info, Pictures, Origin & History

If you’ve ever had the fortune to meet a Munchkin cat, you already know how friendly, tiny, and full-on cute they are. The...

Is My Cat Stressed or Sick? Vet-Reviewed Signs & Ways to Help

Cats can struggle with change just as any species, so in times of stress, it is important to be more cautious of their...

How to Make Your Cat Feel Safe in a New Home: 8 Vet Approved Steps

As creatures of habit and sticklers for routine, adjusting to life in a new environment can be challenging and even scary for cats....

Let’s Hear It For the Moggies! An Ode to Mixed-Breed Cats

Hi, I’m Dr. Karyn! Read my introduction to learn more about me and meet my five hilarious cats: Clutch, Cyril, Alex, Zelda, and...

Keep reading

Why Does My Cat’s Poop Smell So Bad? 8 Vet-Verified Reasons & Solutions

As much as we all love our cats, cleaning out their litter trays is unlikely to top any cat lover’s list of favorite tasks. If your cat’s poop smells bad, this can make the job even worse! Smelly cat poop...

constipated cat in the litter box

How to Train Your Cat: Vet-Approved Cat Training Guide

Cats have reputations that precede them. Even cats that are incredibly affectionate and what some owners might call “dog-like” can be incredibly headstrong. Cats simply don’t enjoy doing something that isn’t on their agenda. Because of their strong characters, there...

cat sits on a sofa and sniffs owner finger

Is There Mercury in Cat Food? Vet-Verified Facts & FAQ

As a cat lover, you understand how irresistible fish is to our feline friends. Because we naturally want to feed them the best we can and reward them with their favorite treats, it’s normal to reach for the fish-flavored kibble...

woman reading pet food label

Do Feral Cats Meow? Vet Reviewed Facts

If you own a cat, you know many are anything but quiet. Cats meow at you for any reason, and some constantly chatter throughout the day. While feral cats may look like regular cats, they behave differently. So do feral...

two-feral-cats

Can Cats Eat Pineapple Leaves? Vet Reviewed Dangers & Advice

Pineapple lovers know the leaves and skin of their favorite fruit have no place in their diet, but cats are rarely as discerning. Many cats enjoy chewing greenery for one reason or another, often not taking the time to check...

Can Cats Eat Pineapple Leaves

How Long Does It Take to Neuter a Cat? All You Need to Know (With Vet-Approved Information)

Any surgical procedure done to your pet can seem like it lasts forever. After all, most people hate being away from their pets, even for a day! If you are planning on getting your male cat neutered, you might be...

neutering cat on a vet's operating table

Why Does My Cat Hide and Sleep in the Closet? 9 Vet-Reviewed Reasons & Tips

Cats are fun pets, but they can exhibit many strange behaviors, one being hiding and sleeping in the closet. We know it can be alarming when your pet suddenly disappears, especially if you aren’t sure why your cat might be...

ginger cat hiding in the closet

7 Best Cat Foods for Weight Gain (High Calorie) in 2026 – Reviews & Top Picks

Some cats are notoriously picky. No matter what food you put out for them, they turn up their noses and walk away from the food bowl. With hundreds of products available, you may struggle to select the right one for...

persian cat eating dry food from bowl

Love Cats? So Do We! Join the Catster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Catster Email Newsletter

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.