Hydroxyzine is an antihistamine approved for humans but often prescribed for animals to treat allergies and allergic reactions. Sold under the brand names Atarax and Vistaril, it's also used to treat nausea, inflammation and anxiety, and is sometimes used for its anesthetic properties. It’s available in tablets, capsules and an oral formulation.
How It's Used
Hydroxyzine works against histamine, a chemical that can cause itching and inflammation. It’s most commonly used for acute conditions, such as insect bites and stings, adverse reactions to vaccinations and blood transfusions, and snakebites. Because it has a sedative property and inhibits activity of the central nervous system, it is sometimes used as a tranquilizer and to treat stress in dogs. Dogs typically receive 1 mg for every pound of body weight every six to eight hours. Ask your vet to recommend a dose before giving your dog the medication.
Cautions and Side Effects
Consult with your veterinarian if your dog suffers from heart, kidney or liver problems. Also use caution when administering hydroxyzine if your dog has glaucoma, an enlarged prostate or an intestinal or bladder obstruction. In addition, don’t give it to pregnant dogs because of the risk of birth defects. Hydroxyzine should not be given to animals receiving sedatives, drugs that depress the central nervous system or epinephrine. Common side effects include dry mouth, increased urination or difficulty urinating, and behavioral changes such as excitability. Signs of overdose include sedation and drowsiness, nausea, breathing problems, seizures and vomiting.