Don’t Get Left Behind When it Comes to Zyrtec for Dogs

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What is Zyrtec for Dogs? 

Zyrtec for dogs is the brand name for a type of antihistamine for dogs containing Cetirizine. Veterinarians and owners use it to treat itching, also called Pruritus, that occurs with conditions like Urticaria (hives) and Atopic Dermatitis. But Zyrtec is also useful for itching of other origins, like insect-bite reactions. 

To learn more about this and much more, keep reading!

Dog ear with Atopic Dermatitis

Is Zyrtec Safe for Dogs?

Some owners may wonder, “is Zyrtec okay for dogs?” when it is not made primarily for animals. The use of these antihistamines for dogs is “off label” or “extra label,” meaning it is not produced exclusively for use in cats and dogs. Luckily, it is widespread for a drug to be “off label.” Generic Zyrtec for dogs is no less safe or effective in treating itching. 

Being “off label” just means that it is essential that the instructions and directions made by your veterinarian are even more important to follow as you cannot rely on the information within the package. 

Apoquel vs. Zyrtec for Dogs – The Difference

We all know how horrible it can be to feel that itching all over your body. It is no longer comfortable for our pets, which is why many veterinarians and owners have hunted for the perfect pet allergy medicine over the years. 

Zyrtec is a type of humane antihistamine that works by blocking some specific receptors within the body. However, the efficacy can sometimes be limited and is only helpful for short-term treatment. 

Apoquel is a different medication aimed to effectively relieve itching and inflammation associated with atopic and allergic dermatitis. Dermatitis means “inflamed skin” and affects animals for several reasons. 

Most often, dermatitis in dogs occurs due to allergies to either airborne substances, like pollen or dust, or food products – commonly dairy or beef. 

Apoquel is a prescription medication made for pets, but the most significant difference is in efficacy. According to studies, Apoquel is far more effective in alleviating itching associated with dermatitis and allergies than other types of antihistamines for dogs. Also, owners can use it for long-term maintenance therapy.

To summarize: Zyrtec for dogs is terrific for once-in-a-while treatment when a dog has an insect bite or has suffered a sudden onset of itching, but if you are looking for long-term treatment, you should consider Apoquel.

The Correct Zyrtec Dosage for Dogs

The zyrtec dosage for dogs per pound is 0.00001oz/lb (0.4mg/0.45kg)  or 0.00001oz/2lb (1mg/kg). 

It is administered as a tablet orally once or twice daily, depending on the severity of symptoms and other health conditions. 

Dog Allergy Medicine for Humans – Yay or Nay?

Zyrtec is an over-the-counter medication that anyone can buy, meaning there’s nothing stopping owners from giving their human allergy medication to their cats or dogs. It is also unlikely to cause any harm if given the correct dosage. 

That said, there are some cases where antihistamines for dogs are not the correct treatment plan and may worsen a condition or even cause untoward reactions within the dog. It is also important to note that antihistamines do not work as well in dogs as for us. Therefore, an antihistamine may not be enough to alleviate your dog’s discomfort.

Therefore, we do not recommend giving your dog Zyrtec without consulting a veterinarian first to ensure your dog receives the best possible treatment. 

What is Canine Zyrtec Used for?

Zyrtec for dogs is primarily to stop acute itching; for whatever reason, this is occurring. Some common causes of itching in dogs include: 

  • Reactions at injection sites. 
  • Hives (Urticaria). 
  • Insect stings and bites. 
  • Mast cell tumors. 
  • Atopic dermatitis.

But how does this pet allergy medicine work? There is something called mast cells within the body, a cell from the immune system. When this cell comes across an allergen, it will release a biochemical molecule called histamine. 

Histamine will then activate its histamine (H1) receptors, causing the symptoms we associate with allergic reactions, like red skin and itching. Zyrtec, or Cetirizine, works by blocking these H1 cellular receptors within the body. Inhibiting the receptors will thereby limit some symptoms and inflammatory reactions. 

Dog with red irritated skin due to allergy

The Efficacy of Zyrtec for Dogs

In humans, our primary mediator of inflammation is histamine – why antihistamines work so well for us. That is, however, not true for our pets. In cats and dogs, histamine is not always the main inflammation mediator present, meaning the efficacy of antihistamines – like Zyrtec – can sometimes be limited. 

If you administer Zyrtec to your dog but believe it is still itching, you should contact your veterinarian to discuss an alternative treatment plan. 

Canine Zyrtec’s Side Effects

The Cetirizine in Zyrtec for dogs does not cross the barrier present between the blood and the brain, meaning it should not cause drowsiness in our pets. In some small animals, however, it has been reported at very high doses. 

Besides drowsiness, although side effects with Zyrtec for dogs are, luckily, rare, there have been reports of some vomiting and increased salivation. 

The medication is fast acting and should stop working within 24 hours, meaning any possible side effects should also disappear by then. If your dog is suffering from any side effects or they are worsening, you should contact your veterinary care provider. 

When Not to Give Your Dog Zyrtec

As a general rule-of-thumb: Never give Zyrtec to dogs without consulting a veterinarian. 

Besides that, be aware that some types of products containing Cetirizine contain Pseudoephedrine or Xylitol. Do not give these to your dog as both products are highly toxic to dogs. 

Do not give Zyrtec to lactating or pregnant females. The efficacy and safety have not been evaluated or studied, so you should not administer it. 

Possible Drug Interactions With Zyrtec

Zyrtec have known to interact with certain drugs, including central nervous depressants. Therefore, be sure to inform your veterinarian if you have given your dog Zyrtec and other types of medication, supplements, and therapies. 

Risk Factors Associated With Zyrtec for Dogs

Zyrtec, and Cetirizine, are generally very safe for dogs to ingest. However, it would help if you used it with caution in pets that suffer from epilepsy, have difficulty urinating, are senior, have glaucoma (an eye condition), or are used as working dogs. 

FAQs on Zyrtec for Dogs

Can I give Zyrtec for my dog with a meal?

You can give the tablet with or without a meal. If given with food, ensure your dog ingests the whole pill. 

What should I do if I miss a dose of Zyrtec for my dog?

Give the next dose when you remember. If you are close to the time, you should have given the next dose; skip the missed dose. Never give a double dose. 

Is it normal for Zyrtec to make my dog tired?

Some small dogs may experience some tiredness if given a high dose. 

How should I store Zyrtec for dogs?

Store at room temperature away from animals and small children. 

Can I give my dog Zyrtec-D?

No, it contains Pseudoephedrine, which is highly toxic to dogs. 

How do I administer Zyrtec to my dog?

Give it orally, with or without a meal. 

Does my dog need a prescription for Zyrtec?

No, it is an over-the-counter medication. We recommend that you contact your veterinarian beforehand, though. 

How does Zyrtec for dogs work?

It works by blocking the H1 receptors within the body, preventing the inflammatory molecule histamine from activating them. 

Animal dog pill

We’ve Got You Covered

If your dog is going crazy because of an insect bite, we all want to help, and in these cases, Zyrtec for dogs can be a much-needed helping hand in alleviating some of the itchings. Just remember always to keep an eye on your dog when giving medication, even if it is over the counter, and hopefully, your best friend will soon be running around itch-free! 

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With a veterinary master's degree from the University of Copenhagen in 2023, this accomplished writer's academic journey culminated in a thesis focused on the "Feasibility of using ultrasound of the abdomen for early diagnosis of necrotizing enterocolitis in neonatal pigs." Additionally, their dissertation delved into the intriguing topic of "Mercury accumulation in Greenlandic sleddogs." Beyond her academic achievements, her passion for animal health seamlessly merges with her love for writing. She excels in harmonizing clinical precision with literary expression, crafting articles that resonate with the heartbeat of her veterinary profession.