Major Uses

Ketoconazole is an imidazole oral antifungal that is primarily used to treat systemic mycoses such as aspergillosis, cryptococcal meningitis, blastomycosis, and histoplasmosis. It can also be useful for treating hyperadrenocorticism in dogs.

Common Precautions

Caution should be used when administering ketoconazole in patients suffering from hepatic disease or thrombocytopenia. While it has been used in cats, this use is controversial and many believe that this drug is not for feline use.

Some negative effects associated with ketoconazole include anorexia, vomiting, and diarrhea. Symptoms of hepatic toxicity, especially cholangio-hepatitis and increased liver enzymes, have been observed in patients. Thrombocytopenia may also occur in animals taking ketoconazole. Patients may also experience a completely reversible lightening of the haircoat.

Ketoconazole should not be used in animals with a known allergy or hypersensitivity to the drug. A veterinarian should be contacted immediately if any negative effects occur or an overdose is suspected.


Ketoconazole should be kept at room temperature and stored in a light resistant, childproof container. It should be kept in a location where it cannot be reached by children or animals.


Ketoconazole is typically used for 10-14 days. For treating coccidioidomycosis in dogs, a typical dose ranges from 5-30 mg/kg twice a day to every other day. For blastomycosis in dogs, a typical dose is between .25-40 mg/kg divided twice daily, or every other day depending on the chosen method of administration. When treating histoplasmosis in dogs, a typical dose is 10-20 mg/kg once or twice a day. Should a scheduled dose be forgotten, it should be administered as soon as possible. If it is nearing time for the next scheduled dose, the missed dose should be skipped in favor of the regularly scheduled dose. Two doses should not be administered at the same time, as an overdose may occur.

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.