Hydroxyzine For Dogs – Uses, Doses and Side Effects

Hydroxyzine for dogs is a canine antihistamine. Your vet may prescribe it to relieve the symptoms of an allergic reaction.

There are a few things you’ll want to know before giving this to your dog. Such as, what is the correct hydroxyzine dosage for dogs? What are the side effects of hydroxyzine in dogs? 

We take a look at some of the most commonly asked questions about this drug.

And don’t forget – if you’re at all concerned about your pet’s medication, then give your veterinarian a quick ring. They won’t mind!

What is Hydroxyzine?

Hydroxyzine belongs to a family of drugs called antihistamines.

Antihistamines are most often taken to relieve the symptoms of allergic reactions, such as itchiness. This itchiness is known as ‘pruritus.’

Antihistamines can also be used to treat anxiety, and to calm patients before general anesthesia and surgery.

These drugs were first discovered in the 1930’s. But, it wasn’t until the 1940’s that they were commonly used.

While the first antihistamines were too toxic for human use, they have since been refined and are commonly, and safely, used today.

Antihistamines work by blocking the action of histamines.

Histamines are compounds in the body which are responsible for the symptoms we experience when we are allergic to something.

Hydroxyzine is an H1 antihistamine

This ‘generation’ of antihistamine also crosses the blood-brain barrier and acts on the histamine receptors in the central nervous system.

This results in a feeling of drowsiness.

These days, another type known as ‘H2 antihistamines’ are commonly used. They have been developed so as not to cause drowsiness.

But for cases of severe pruritus, many still prefer hydroxyzine.

The sedative properties are beneficial in these instances. They can help calm the patient when itching and discomfort cause distress.

This is how hydroxyzine is used on humans. But what is hydroxyzine for dogs?

Can Dogs Take Hydroxyzine?

Dogs are able to take hydroxyzine. In fact, antihistamines are quite often used to treat skin allergies in dogs.

The treatment can be very effective. But, there are also side effects that you should keep in mind. We will look at these later in this article.

So, it is important that you only give this medication to your dog under your vet’s supervision.

Let’s have a look at how hydroxyzine is used to treat dogs.

Hydroxyzine For Dog Allergies

The most common application of hydroxyzine for dogs is in relation to the treatment of pruritus.

Pruritus is not a disease in itself. It is a symptom of an underlying disease or condition.

Pruritus is often the result of allergies, infections, or parasites.

One study found that 54% of dogs with atopic dermatitis that had been given antihistamines to treat the condition responded favorably.

A number of different antihistamines were used. Of the types administered, hydroxyzine was one of the most effective.

There is a wide variety of reasons your dog may be itchy. So, your vet will first determine what is causing the problem and treat the underlying issue.

After an examination, they may deem it appropriate to prescribe an antihistamine as part of the treatment plan.

Hydroxyzine is a common choice. But it is not the only antihistamine that vets use.

Hydroxyzine for Dog’s Anxiety

In humans, hydroxyzine is sometimes prescribed to treat anxiety. Hydroxyzine for dogs is not often used in this capacity.

But, your dog may be displaying signs of anxiety because of discomfort.

If this discomfort is due to an allergy, a skin infection, or dermatitis, your vet may prescribe an antihistamine to relieve the symptoms and make your pooch more comfortable.

What Form Does Hydroxyzine for Dogs Come In?

Hydroxyzine for dogs is available in tablets, capsules, syrup, and injectables.

Your vet will determine which form will be the best way to treat your dog.

Hydroxyzine HCl for Dogs or Hydroxyzine Pamoate for Dogs – What is the Difference?

Both hydroxyzine HCl (hydrochloride) and hydroxyzine pamoate have the same active ingredient, hydroxyzine.

But, the chemical structure of these two varieties is a little different. This affects how the drug works.

As a result, hydroxyzine pamoate is what doctors will prescribe to human patients to treat anxiety.

Hydroxyzine hydrochloride is the most common treatment for pruritus in dogs.

How Much Hydroxyzine Can I Give My Dog?

Treating dogs with antihistamines can take some trial and error as each animal reacts very differently.

So, it’s impossible to recommend ‘across the board’ dosages that will produce good results.

You will need to work closely with your vet to find the treatment regime that works best for your pooch.

What is the Protocol for Using Hydroxyzine for Dogs?

Your vet will work to determine the appropriate dosage according to a few factors.

These include the severity of the symptoms, the size of your dog, and any existing treatments or illnesses your dog has.

Generally, a 7 to 10-day therapeutic trial will reveal if the treatment is going to work.

After this, your vet will assess the situation and decide whether to prescribe antihistamines that are to be taken on a more regular basis.

They may even prescribe another type of antihistamine for your dog.

Or decide that treating your dog’s itchiness another way will yield the best results.

Hydroxyzine for Dogs – Side Effects

If your dog is taking hydroxyzine, you should keep the possible side effects in mind. Monitor your dog for any symptoms.

They vary from mild to severe. The most common side effect is drowsiness. But, sometimes this is the desired outcome.

Other, rarer side effects include:

• excitement,
• gastrointestinal disturbances
• an increase of pruritus (if the drug is given in high doses)
• cardiovascular problems (particularly in the case of an overdose)

More serious side effects can include coma and apnea. Apnea means that the patient stops breathing temporarily.

Some dogs taking other types of antihistamines have also experienced vomiting.

Does Hydroxyzine for Dogs Interact with Other Drugs?

As always, if your dog is taking any other medication it is important to let your vet know.

Hydroxyzine for dogs is known to interact with other medications.

For example, it can counteract the effects of warfarin.

It is vital that you inform your vet about all other medications your dog is taking before commencing the treatment.

When not to use hydroxyzine

If your dog has any of the following, taking antihistamines is not usually recommended:

• liver or heart disease
• high blood pressure
• glaucoma
• hyperthyroidism
• a history of seizures
• urinary retention
• intestinal atony

There is also not much evidence regarding the effects that antihistamines have on a pregnant or breastfeeding animal.

So, if your dog is pregnant it would be wise to discuss this with your vet.

Hydroxyzine for Dogs – Should you use it?

We always recommend that you follow your vet’s advice when it comes to canine medication.

Hydroxyzine is a drug that can bring much relief to your furry friend when they are not well.

But it needs to be taken under the supervision of a professional.

Have you ever had to use hydroxyzine for dogs?

Feel free to share any questions and experiences in the comments section below.

Readers Also Liked

• Best Dog Food For Seniors With Sensitive Stomachs
• Best Dog Food for Small Dogs with Sensitive Stomachs
• Can Dogs Eat Corn?
• Impulse Control For Dogs
• Hydrogen Peroxide For Dogs – Vomiting, Ears, Wounds, Other Issues
• What Is A Pedigree Dog?

References

• Tegzes, J.H et al. Coma and apnea in a dog with hydroxyzine toxicosis. Veterinary and Human toxicology, 2002
• MSD Veterinary Manual – Pruritus in Dogs
• MSD Veterinary Manual – Behavioral Problems of Dogs 
• US National Library of Medicine: MedlinePlus – Hydroxyzine
• Emanual, M.B, Histamine and the antiallergic antihistamines: a history of their discoveries.
• Church, M.K., Church, D.S., Pharmacology of Antihistamines Indian Journal of Dermatology, 2013
• US National Library of Medicine: PubChem – Hydroxyzine
• Zur, G., et al Antihistamines in the management of canine atopic dermatitis: a retrospective study of 171 dogs (1992-1998).
• Eichenseer, M., et al, Efficacy of dimetinden and hydroxyzine/chlorpheniramine in atopic dogs: a randomised, controlled, double-blinded trial The Veterinary Record, 2013
• Bridgood, T., What’s New in Clinical Pharmacology? American Animal Hospital Association
• Book: Church D.B., Small Animal Clinical Pharmacology Elsevier Health Sciences, 2008
• PubChem Open Chemistry Database
• PDR (Prescribers Digital Reference)