Major Uses

Hydroxyzine is used in animals as an antihistamine to treat severe inflammatory and allergic conditions. This drug can be used to treat skin redness, itchiness, swelling, pain, increased heart rate and drops in blood pressure. Atopy in dogs, a pruritic (itchy) skin disease, is commonly treated with hydroxzyine. The drug has anti-nausea effects that can be useful in treating motion sickness. In addition, it can also be used as a mild sedative.

Common Precautions

Hydroxyzine may cause adverse side effects including sedation, lethargy, vomiting, diarrhea and lack of appetite. When treating patients with prostatic hypertrophy, bladder neck obstruction, severe cardiac failure, angle-closure glaucoma, or pyeloduodenal obstruction, this medicine should be used with caution.

There have been reports of dogs sporadically having a hyperexcitability on hydroxyzine. Some dogs have developed fine rapid tremors, whole body tremors and, seldom, seizures while receiving this drug. Cats can develop polydipsia, depression, or behavioral changes when being treated with hydroxyzine.

Hydroxyzine should not be used in pregnant animals due to the strong possibility of birth defects. Hydroxyzine should not be used in animals with a known allergy or hypersensitivity to the drug.


The oral form of hydroxyzine should be stored at room temperature, in a tight, light-protected container. The injectable form should be stored at room temperature and protected from freezing.


Hydroxyzine is available in oral and injectable forms. For oral tablets, hydroxyzine is available in 10mg, 25mg, 50mg, and 100mg. It is also available in 2mg/ml oral syrup. An injection concentration of 25mg and 50mg is available as well.

A typical dose for dogs is 1mg per pound (2mg/kg) two to three times daily. For cats, hydroxzyine is dosed at 0.5 to 1mg (1 to 2mg/kg) or 5 to 10 per cat every 8 to 12 hours. The prescription should be completed in its entirety, unless told otherwise by a veterinarian. If the prescription is not completed, it could result in the animal relapsing.

Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.

This information is for general reference only and should not be used for the diagnosis or treatment of any condition of your pet. It's intended as a general reference, this information may not include all possible uses, precautions, directions, reactions (including allergic), drug interactions, or withdrawal times. Always consult your local veterinarian and have your pet examined for any advice concerning the diagnosis and treatment of your pet, including which products and doses are most appropriate. Any trademarks are the property of their respective owners. VetDepot is not a pharmacy. All prescription products are dispensed by our Pharmacy Partner. Article last updated 2/2014.