How Much Zyrtec Can I Give My Dog

You must have heard of the name Zyrtec as it is an anti-allergic medication often used by humans. It functions as a blockage in the allergy paths of the body and also inhibits histamine which means the medication itself is an anti-histamine drug.

The other name of Zyrtec is cetirizine, and it is also recommended by the vets for the dogs regarding the same problem, allergy. But dosage must be different so, have you ever thought about how much Zyrtec can I give my dog? If not, this is the right time.

Before we discuss the right dosage, some of you would be wondering if the drug is safe for dogs or not. Well, unlike many other things, Zyrtec is safe for both humans and dogs, but there are exceptions.

So, it is not unsafe for most of the pups, but the owner has to be cautious in some cases. What are they? You’ll know in the article.

Here, we are going to tell you the normal recommended dosage of Zyrtec, its side effects, uses, efficacy, precautions, and every other minor detail one should know as a pet owner.  Let’s get started!

How Much Zyrtec Can I Give My Dog

Zyrtec/Ceterizine Dosage in Comparison with Others

General NameMarketed NameAvailable Fromsupto 10lbs10-20lbs20-30lbs30-50lbsover 50lbsDaily Dosage
ChlorpheniramineChlor-Trimeton4 mg tablet½ tab1 tab2 tab2 ½ tab3 tab2-3X daily
DiphenhydramineBenadryl2.5 mg/ml syrup1 tsp2-3X daily
25 mg cap/tab1 cap/tab1 cap/tab1-2cap/tab2-3 tab2-3X daily
CeterizineZyrtec10 mg tablet¼ tab¼ tab½ tab½ tab1 tab1 X daily
LoratidineClaritin10 mg tablet¼ tab¼ tab½ tab½ tab1 tab2X daily
ClemastineTavist-11.34 mg tablet½ tab½ -1 tab1 tab1-2 tab2X daily
HydroxyzineAtarax10 mg tablet1 tab2-3X daily
25 mg tablet1 tab2-3X daily
50 mg tablet1 tab1-2 tab2-3 tab2-3X daily
AmitriptylineElavil10 mg tablet1 tab1 tab1 tab2X daily
25 mg tablet1 tab2X daily
50 mg tablet1 tab2X daily
CyproheptadinePeriactin4 mg tablet1/2-1 tab2-3 tab4-5 tab6-7 tab8 tab2X daily

Recommended dosage of Zyrtec:

Being a careful and responsible pet owner, you must keep a check on your dog and its medications. If your vet has prescribed Zyrtec for your dog’s allergy, and you are not sure about the dosage, we are here to guide you.

The dosage of medication depends on various factors including the dog’s health condition, age, and size so is the case with Zyrtec. If you want to know how much Zyrtec can I give my dog, you should first talk this out with your dog’s vet as it should be the priority.

The vet usually asks for the weight of the dog when you take your dog to him, and then prescribes the medication. So, you should always keep yourself updated with your dog’s weight.

Generally, the recommended dosage of Zyrtec is 1 mg for each kg of the body weight of your dog. In other words, you should 0.5 mg of Zyrtec for the 1 lb bodyweight of your dog.

Only one dose should be given each day, as exceeding its amount can cause severe side effects on the dog’s health. However, if due to any reason you are planning on changing the dosage plan, it is better to discuss it with the vet before taking any decision.

Dosage of Zyrtec Tablet:

Zyrtec tablet comes in two different dosages, one is a tablet of 10 mg and the other is of 5mg. Which one should you administer to your dog? Well, if your dog weighs anywhere around 10 to 50 lbs, you should opt for the 10 mg tablets, they are sufficient and safe for them.

However, if the weight of your dog is below 10 lbs but more than 5 lbs, you should cut the tablet of 10 mg into half, and give one at a time, or 5 mg tablet would be great for them.

Moreover, the dogs who weigh even less than 5 lbs should be allowed to take just a quarter of the 10 mg tablet or cut the 5 mg tablet into half for them.

Lastly, if the dog breed is huge, and it weighs more than 50 lbs, you can give 2 tablets of 10 mg according to its weight. Until you are keeping the dosage aligned with the body weight, it is not going to exceed the normal dosage.

Liquid Zyrtec intake:

It must be hard for you to cut the tablet evenly into halves and quarters if your dog is small. We understand your misery hence, for those pet owners, a liquid form of Zyrtec is ideal. Yes right! Zyrtec is available in liquid form as well besides tablets, which makes it easy for most of the owners to administer the medicine to their dogs.

You can simply use a dropper or injection to squirt the medication into the dog’s mouth. This way there is no risk of spitting out the medication, unlike tablets. Also, another effective way is to sprinkle the dose over the dog’s meal, so that it may unknowingly take the medication without any problem.

What are the side effects of Zyrtec?

There are no significant side effects of Zyrtec if you let your dog take the proper dosage, just as prescribed by the vet. Yes, right! We know it is something you need to assure your dog’s safety, and you got it. Among a variety of safe medications which have nonexistent side effects, Zyrtec is the one.

Just follow your vet’s lead, act upon his guidelines, and your pet is never going to face any challenges,

But what if you overdose on the medication? Overdosing of Zyrtec might have some side effects on a few dogs, but that condition is also rare. We know this is hard to believe, but yes, it’s the truth. Research has proved that if a dog overdoses even 200x the normal amount, it will not show any severe side effects.

Why does that happen? Dogs naturally have great tolerance against this medication, and the excess amount in their body doesn’t harm it. But this doesn’t mean that Zyrtec cannot have side effects. No, this is not the case. There are exceptions, in which the medication may affect the dog’s health. Let’s see how!

When you administer the medication to the dog, some of them might show some side effects, the most common of which is drowsiness. Why are these side effects acting on your pup? The reason is that it might be allergic to the medication as well. In case the dosage is extremely high, or the dog is allergic to it, it will get drowsy right after the first dose.

What to do in this situation? We would recommend you immediately discontinue giving the drug to your pup and consult the vet as soon as possible. The veterinarian will understand the situation better, and guide you the right thing.

Some of the other side effects of the medication can be:

  • Vomiting
  • Increased salivation
  • High excitement level
  • Tiredness
  • Constipation
  • Dizziness

No dog can communicate and tell you easily what it is experiencing so, it is you who has to predict what your dog goes through. Monitor its condition for the next few hours after giving it the medication. Especially in the case of small dogs, you should be careful because the percentage of small dogs is higher than the other among the rare cases.

How to safely administer Zyrtec to your dog?

Although Zyrtec doesn’t have any serious side effects, a pet owner should do the following for the safer side:

  • If the dog is facing any health changes, update the vet as soon as possible.
  • Monitor the dog after it takes medication to assess either it is behaving normally or having some side effects.
  • Tell the vet about any other medication you are giving to the dog also, make sure you are giving the right dose.
  • Give a try to other medications as per the vet’s recommendations.

Zyrtec Drug interactions:

Usually, drugs interact with other medications when they are taken at the same time when your dog is on another medication as well. In the case of Zyrtec, it can interact with some specific drugs and cause serious side effects on the dog’s health. To prevent this condition, you need to know about all those drugs, have a look!

  • Pseudoephedrine (found in nasal decongestants)
  • Topical or oral antihistamines (for example chlorpheniramine and diphenhydramine)
  • Muscle relaxers (for example carisoprodol and cyclobenzaprine)
  • Sleep medications or anti-anxiety pills (for example clonazepam, diazepam, zolpidem, lorazepam, alprazolam)
  • Opioids (for example morphine, hydrocodone, codeine)

Sensitivity and allergic reaction:

An anti-allergy medication causing an allergic reaction to the dog! Seems strange, right? We know it is, but that’s true. Some dogs are allergic to specific medications, and Zyrtec can be one of them.

If your dog is showing signs of anaphylaxis, it can get worse with time so, reach your vet as soon as possible. The allergic reaction due to a drug interaction or any other cause can show symptoms of:

  • Swelling of the face, muzzle, tongue, or paws
  • Involuntary muscle twitching
  • Shock
  • Cold gums and moth
  • Abrupt loss of bowel and bladder control
  • Increased heartbeat
  • Confusion
  • Difficulty in breathing
  • Extreme itchiness
  • Hives

Why is Zyrtec mainly given to the dogs?

When a pup reaches its age of about 1 to 3 years, there are chances it may suffer from skin issues or allergies. In such cases, most of the vets prescribe Zyrtec to your pup.

The most common condition is dermatitis, in which your dog feels extreme itchiness on the skin. But there are other symptoms as well which shows the need for this medication.

Let us have a quick overview of these issues:

  • Excessive licking
  • Too much chewing of body parts like paws or legs
  • Excessive head shaking
  • Swelling in various skin areas
  • Hair loss
  • Excessive face rubbing
  • Skin itchiness and irritation that leads them to scratch

If your dog is showing any of these symptoms, you should immediately seek professional care for them before it gets worse.

Are all forms of Zyrtec safe for dogs?

Forms of Zyrtec might be a bit confusing for you, but yes, Zyrtec comes in different types. Let’s see how! The Zyrtec which is safe and usually recommended for dogs is the one having only one active ingredient, which is cetirizine.

However, the other types of Zyrtec may include multiple ingredients that can be harmful to the dog.

Let’s review an example. Zyrtec-D is one of the most common types of Zyrtec, but it isn’t safe for dogs. The pseudoephedrine in its formulation is an ingredient that is very dangerous for dogs or any other pet.

So, it is very critical to ensure that what is the active ingredient of the medication which you administer to your dog. Research has shown that even a single dose of Zyrtec D can kill the dog, especially the small ones, so never get mistaken for it.

Can Zyrtec be harmful to dogs?

We have discussed that Zyrtec if given in proper dose, cannot harm the dog, and even overdosing effects in very rare cases. Then how come dogs have worse effects after taking this medication. Let us tell you!

There are some conditions, in which this medication can harm the dog besides helping it in its bad. You should be extra careful in such circumstances to avoid any serious issues. Following are the conditions in which it is a bad idea to let your dog have Zyrtec.

Breastfeeding dog:

If a mother dog is breastfeeding its pups, you must be very careful of what it is eating because all the nutrients will be transferred into the pup’s milk. So, if the mother dog is taking Zyrtec, it may pass the anti-allergic ingredients to the puppy as well which might have a negative effect as they are too strong for such a little creature.

Pregnant dogs:

The same reason goes for pregnant dogs. The fetus dog is taking all the nutrients and food from the mother’s body hence, there is a risk it may take the ingredients of Zyrtec causing side effects. However, if the benefits of the Zyrtec drug overweight the risks, it is an exception where the risk is worth to be taken.

Liver or Kidney Problems: 

Giving Zyrtec to a dog suffering from liver and kidney problems will only worsen their condition as Zyrtec causes urine retention in dogs so, never plan on giving a dog such medication.


As discussed, some dogs are allergic to the medication so in other words, we say they are hypersensitive to Zyrtec. Do not give your dog medication in this condition.

Bottom line:

After reading the article, we hope that you have now a complete idea of the fact that how much Zyrtec can I give my dog. Although the medication is used to deal with atopic dermatitis or mild to moderate environmental allergies, sometimes it can show side effects as well so always be in touch with your vet about whatever happens with your dog. Don’t miss a single dose, and avoid overdosing on your dog to keep it in ideal health condition.

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