How Much Zyrtec Can I Give My Dog?

The dose of Zyrtec for dogs is approximately 0.5 mg per pound, or 0.5 mg/lb., 1-2 times per day, and not to exceed 20 mg per dose. Zyrtec comes in 5 and 10-milligram tablets. You should administer it orally only. Buy a pill cutter if your dog needs half tablet dosing to maintain accuracy.

For example:

5 lbs. dog = 2.5 mg, or 1/2 of a 5 mg tablet

10 lbs. dog = 5 mg, or one 5 mg tablet

20 lbs. dog = 10 mg, one 10 mg tablet or two 5 mg tablets

30 lb. dog = 15 mg, or three 5 mg tablet

50 lbs. dog = 20 mg, two 10 mg tablets

75 lbs. dog = 20 mg, two 10 mg tablets

100 lbs. dog = 20 mg, two 10 mg tablets

We hope you are clear about the dosing of Zyrtec for dogs. But there are so many things involved regarding safe usage of Zyrtec for dogs. We will answer every concern you have in the next paragraphs. Let’s start with the most basic question:

What is Zyrtec?

Zyrtec is a human antihistamine medication that can also treat allergies in dogs. It’s over-the-counter medicine, and it comes in tablet form.

Zyrtec relieves symptoms like itching, sneezing, watery eyes and runny nose by blocking histamine production in the body. It also blocks other chemicals that are released by cells during an allergic reaction.

It’s important to note that Zyrtec for dogs is not a cure for allergies. It can help your dog feel better while they’re dealing with the allergy, but you’ll still need to take them to see their vet regularly so they can make sure there aren’t any underlying issues that might cause their allergies.

When is Zyrtec used in dogs?

There are many reasons why your pet may be itchy, but one of the most common is seasonal or environmental allergies. Zyrtec is an antihistamine that veterinarians use to treat mild to moderate itching associated with these types of allergies. These are the following conditions when Zyrtec is used:

Zyrtec is the perfect prescription for your dog if he has a skin condition, suffers from allergies, or is suffering from insect bites.

Atopic dermatitis

The most common use of Zyrtec in dogs is to treat atopic dermatitis, which causes excessive itching and scratching. The drug treats the symptoms of atopic dermatitis by reducing histamine levels in your dog’s body so that he can feel less itchy and scratch less often.


Another use for Zyrtec in dogs is to treat urticaria, or hives. This condition causes wheals (red bumps) on your dog’s skin that are extremely itchy, making him want to scratch them off all day long. By suppressing histamine levels in your dog’s system with this medication, you can help him feel less itchy and prevent additional inflammation of his skin.

Itchy skin

It is uncomfortable for your dog and can cause him to scratch excessively. If you notice that he is scratching more often than usual or if his skin looks red and inflamed, it may be time to talk with your veterinarian about whether Zyrtec would be appropriate for him.

Environmental allergens

It can also cause your dog to have itchy and inflamed skin. If you live in a particularly dusty area or near fields where crops are being grown, for example, it may be worthwhile to talk with your veterinarian about giving your pet Zyrtec.

Chronic allergies

It can be very difficult to manage, but Zyrtec may be able to help with the symptoms. If you are unsure if your dog’s itchy skin is due to allergies or another condition, talk with your veterinarian about whether Zyrtec would be an appropriate treatment option for him.

Insect bites

Finally, some veterinarians will prescribe Zyrtec to dogs with insect bites because they know that the drug will help relieve any pain associated with those bites as well as reduce swelling and inflammation around them – all while keeping your pup calm so he doesn’t bite himself further.

Side effects of Zyrtec in dogs

Zyrtec is a non-sedating antihistamine that is used to relieve allergy symptoms. While the drug is generally safe for your pooch, it can cause certain side effects, such as:

Excessive salivation

Excessive salivation can be one of them. This means that your dog may drool more than usual, and it may be hard to keep them from swallowing their saliva after they eat or drink something.


Another possible side effect is vomiting. If your dog vomits while taking Zyrtec, this could mean that they’re not tolerating the drug well and you should take them off it immediately.

Difficulty in urination

Your dog may also have difficulty urinating while on Zyrtec. This could be due to the drug’s effects on their kidneys, which is why you should take them off it if they start having this issue.

Difficulty in breathing

Another possible side effect is difficulty in breathing. This means that your dog may have a hard time getting enough oxygen into their lungs, which could lead to a cough or wheezing. It’s important to note that if your dog has asthma or other respiratory issues, they should not take Zyrtec because it could make these problems worse.


Your puppy may also suffer from impulsiveness. If your dog is taking Zyrtec and you notice them acting more rashly than usual, this could mean that they’re not tolerating the drug well and you should take them off it immediately.


The last possible side effect of Zyrtec is lethargy. If your dog becomes extremely tired while taking this medication, this could mean that they’re not tolerating the drug well and you should take them off it immediately.

Frequently asked questions

Here are the answers of some of the most frequently asked questions about Zyrtec and its usage in dogs:

How long does it take for Zyrtec to work on your dog?

It depends on many factors, such as the age and severity of their disease, their weight, and any underlying health conditions they may have. Generally, though, you should see an improvement in symptoms within one hour of administering Zyrtec.

Is Zyrtec safe for pregnant and nursing dogs?

It’s generally considered to be safe for use in pregnant dogs, but it is not recommended while nursing your dog. This is because Zyrtec can be excreted through breast milk, which could potentially cause harm to your baby.

Can an overdose of Zyrtec kill your dog?

Yes, severe overdose of Zyrtec can kill your dog. However, the likelihood of this happening is pretty small. In fact, most people have never even heard of an overdose of Zyrtec in dogs.

What if you missed a dose of Zyrtec to your dog?

If you miss a dose, give the next dose as soon as possible. Do not double the dose to catch up. If it’s almost time for the next dose, skip the one you missed and go back to your regular schedule.

What if you overdose your dog on Zyrtec?

Don’t panic!

Zyrtec is a safe and effective treatment for allergies in dogs, but it’s important to follow the recommended dosage. If you accidentally overdose your dog on Zyrtec, don’t worry—you can easily reverse any potential damage by stopping immediately.

If your dog experiences any side effects from taking too much Zyrtec, contact your vet immediately.

If no side effects are seen, continue using the recommended dose of Zyrtec until your dog’s allergy symptoms have been resolved.

Are there any alternatives for Zyrtec?

If you’re looking for an alternative to Zyrtec, I suggest Benadryl and Claritin. They are both antihistamines that work to relieve symptoms of allergies and allergic reactions such as hay fever, runny nose, sneezing and itching eyes. They can also help relieve symptoms of hives and itching caused by eczema.

Benadryl is a medicine that contains diphenhydramine which is an antihistamine. It works by blocking the effects of histamine, a chemical that causes allergy symptoms like sneezing, runny nose and watery eyes. However, be careful of the doses of the Benadryl. Some complained that Benadryl killed their dog.

Claritin is another option when it comes to treating allergies and other symptoms associated with them. It contains loratadine which is an antihistamine that works by blocking the effects of histamine on your body’s cells responsible for producing allergic reactions such as sneezing and runny nose (among others).

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