Major Uses

Clemastine fumarate is an antihistamine most commonly used to treat the symptoms of allergies in dogs and cats. Clemastine fumarate treats acute inflammatory and allergic conditions including itchy skin, snake bites, vaccination reactions, bee stings, and insect bites.

Common Precautions

Side effects most commonly associated with the use of Clemastine fumarate are sedation, paradoxical hyperactivity, and dry mouth in dogs and diarrhea in cats.

Clemastine fumarate should not be administered in animals with a known allergy or hypersensitivity to the drug. Clemastine fumarate should be administered with caution in pregnant animals and animals with known prostate and bladder conditions, heart ailments, and glaucoma. Clemastine fumarate may possibly interact with other drugs including CNS depressant medications and Monoamine Oxidase Inhibitors. This should be discussed with a veterinarian. Emergency veterinary care should be sought if an animal experiences any unusual symptoms.


Clemastine fumarate oral tablets should be stored at room temperature in a tight, light resistant container.


Clemastine fumarate is available in 1.35 mg and 2.68 mg tablets.

A typical dose range for Clemastine fumarate is 0.05-0.1 mg/kg PO q12. Dose 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.

If a dose is missed, it should be administered as soon as possible. If it is almost time for the subsequent dose, the missed dose should be skipped and the regular administration schedule resumed. Two doses of Clemastine fumarate should not be administered at the same time.

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.