Hydroxyzine Dosage Chart for Dogs: Risks, Side Effects, Dosage, and More

When your dog is incessantly scratching as a response to itchy skin or allergies, you can offer some help. Although you can treat your own allergies with over-the-counter medication, those often include other ingredients that aren’t safe for dogs. But your vet can prescribe single-ingredient medication to help your fussy pup experience some relief. Learn more about hydroxyzine, including when dogs may need it, what the right dosage is, and what alternatives you might consider. Always consult with a vet before giving your pet any medication!

When Do Dogs Need Hydroxyzine?

Technically, hydroxyzine is not a pup-specific medication. It was initially created for humans but vets have been prescribing it “off-label” for use in dogs because of its efficacy with certain symptoms.

Motion Sickness

This symptom is more frequently seen in puppies than older dogs. However, it is quite common for dogs to experience motion sickness, which renders any ride (whether to the vet or dog park) uncomfortable. Hydroxyzine helps to relieve this discomfort for your pup, which makes rides bearable and even enjoyable.

Allergic Reactions

Hydroxyzine may also be used to treat allergic reactions in dogs, which manifest in various ways, including itchiness and swelling.

Seasonal Allergies

Dogs that suffer from seasonal allergies experience a range of symptoms, including itchy eyes and skin. Hydroxyzine may be used in some cases though your veterinarian makes that determination based on your pup’s specific needs. They may also suggest alternatives.

Atopic Dermatitis

When atopic dermatitis is present in dogs, dogs experience excessive itchiness. According to the Cornell University College of Veterinary Medicine, this skin disease affects between 10-15% of all dogs.

Hydroxyzine Side Effects and Risks in Dogs

As with any medication, there are some associated side effects or risks. In most cases, your dog may just get a bit drowsy after administration. However, your dog may respond in the opposite way and display uncharacteristic excitement. Other side effects include tremors, seizures, and constipation. Additionally, your pup may experience a dry mouth and more thirst than usual, so it’s vital they have access to plenty of fresh water after administration.

Signs of Hydroxyzine Overdose/Allergies in Dogs

When you notice a more severe side effect like tremors or a seizure, your dog needs veterinary attention. In cases of overdose, you may notice excessive excitability or drowsiness, your pup may stumble or pass out, and their body temperature may be higher than normal. In these cases, you must contact poison control right away.

The ASPCA Animal Poison Control Center’s phone number is (888) 426-4435 and it’s open 24 hours a day, 365 days per year.

When is Hydroxyzine Not An Option for Your Dog?

There are certain situations in which hydroxyzine is not suggested for dogs. For example, if your pup has a urinary or stomach obstruction, this medication should not be used. The same goes for dogs with heart failure or who are allergic to cetirizine. Vets are extra cautious with dogs that are pregnant or that have seizure disorders. Each case should be reviewed thoroughly with a transparent medical history to reduce the risk of overdose or an allergic reaction.

Hydroxyzine for Dogs Dosage Chart

Alternatives to Hydroxyzine for Dogs

Oclacitinib

This medication, also known as Apoquel, comes in tablet form and helps to relieve allergies by inhibiting a chemical signal in your pup’s immune system. As a result, dogs experience relief from symptoms like itching and inflammation. This is a long-term allergy management solution and the side effects like diarrhea and vomiting are rare. Most pups respond well to this medication. The downside is it’s a bit expensive and only suitable for dogs over a year old.

Cytopoint

This is a monthly injection and works by binding to the itch-triggering chemical signal in your pup’s body. Each injection lasts between three to four weeks. The onset is fast with Cytopoint, typically taking one to two days to reduce itching. It doesn’t suppress the immune system like some other options and instead has a specific target. It can be used alongside other medications.

Immunotherapy

This alternative to hydroxyzine is either an injection that’s administered every one to three weeks or an under-the-tongue medication that you administer every 12 hours. It works through exposure, starting with small amounts of allergens your pup is allergic to. Over time, those allergens are increased in the injection until your pup eventually becomes desensitized.

Environmental Changes

In some cases, you can help reduce allergy flare-ups by making environmental changes. You may need to change to a medicated shampoo to clear yeast or bacterial infections, you can vacuum and wash more frequently to get rid of dust mites, and you can also use flea protection to prevent allergy symptoms from flea saliva.

Dietary Changes

If your pup is dealing with food allergies, dietary changes can help reduce allergy symptoms.

Cyclosporine

When your pup is dealing with symptoms relating to allergies, you can try cyclosporine, which is also known as Atopica. This is a tablet you administer twice per day for the first two weeks and then you switch to once per day to maintain the protection. It works like other alternatives and inhibits a chemical signal in your pup’s immune system.

Essential Fatty Acids (EPA/DHA)

This alternative is available in different forms, including capsules and liquids taken by mouth. It’s not a stand-alone treatment for allergies, but it does help to reduce how much medication your pup takes by decreasing inflammatory signals in their body.

Steroids

Available in topical and oral formulas, steroids can be administered at home. However, there are also injectables that can be administered by a veterinarian. They work by suppressing chemical and cell signals in your pup’s immune system. This is especially effective when treating ear infections because it reduces swelling in the ear canals.

How to Treat Hydroxyzine Overdose in Dogs

If you suspect hydroxyzine overdose in your pup, the poison control line will offer specific instructions to help. The ASPCA confirms that in cases of antihistamine toxicosis, the response in pups varies greatly depending on the dose. They also confirm that the most common reported side effects include depression at lower doses but higher doses tend to result in hyperactivity and eventual seizures. These symptoms have been noted as quickly as 10 minutes after ingestion and up to 11 hours later. In some cases, these symptoms lasted for six hours but in other cases, the symptoms persisted for up to seven days.

If a pup is symptomatic, treatment requires veterinary care to assess any life-threatening symptoms. The anticonvulsant that vets typically administer following a hydroxyzine overdose is Diazepam. They administer it intravenously or intramuscularly as a workaround to prevent the excitability the medication often produces in dogs. Additionally, your vet may administer barbitautes, isoflurane, dopamine, or norepinephrine.

Conclusion

Hydroxyzine falls under the category of antihistamine and is used in dogs “off-label” primarily to treat allergies. However, there are other treatments for allergies in dogs that may be more effective than hydroxyzine. Ultimately, your veterinarian decides which treatment option may be best for your pet. If hydroxyzine is prescribed, mild side effects may include drowsiness. However, in cases of allergy to the medication or overdose, your pup may experience seizures.