Ketoconazole for Dogs: An Affordable Antifungal Medication for Skin Infections
Key takeaways:
Ketoconazole (Nizoral) is an antifungal medication most often used to treat Malassezia yeast skin infections in dogs. It may also be used for other fungal infections.
Your veterinarian will determine the best dosage of ketoconazole for your dog. Ketoconazole is usually given to dogs once or twice a day.
The most common side effects of ketoconazole are gastrointestinal issues, but some dogs may develop signs of liver toxicity.
Table of contents
Fungal infections are common in dogs. Symptoms of fungal infections in dogs include itchiness, skin sores, and hair loss.
If left untreated, a fungal infection can cause a dog discomfort and lead to serious health problems. That’s where antifungal medications such as ketoconazole (Nizoral) come in. Below, we discuss how ketoconazole is used to fight fungal infections in dogs, the antifungal’s potential side effects, and more.
Ketoconazole for dogs at a glance
Common names | Ketoconazole (Nizoral) |
What it treats | Fungal infections |
How it comes (forms) | Oral tablets and topical products, including sprays, shampoos, wipes, and creams |
Common side effects | Loss of appetite, vomiting, diarrhea, weight loss |
Average cost | $25-$36 for a 30-day supply of tablets |
What is ketoconazole for dogs, and what is it used for?
Ketoconazole (Nizoral) is an antifungal medication that treats fungal infections in dogs. It works by stopping certain enzymes found in fungal cells, which limits fungal growth. At higher dosages or when taken for longer periods of time, ketoconazole can kill fungal organisms. Ketoconazole is commonly used to treat the below types of infections.
Search and compare options
Malassezia infections
Malassezia is a fungal yeast that’s commonly found on dogs’ skin, feet, and ears. Overgrowth of Malassezia can cause a secondary infection in dogs. This often occurs in dogs with skin allergies.
Ringworm
Ketoconazole is sometimes prescribed to treat ringworm infections in dogs. Oral ketoconazole is often recommended when a ringworm infection has spread to many areas on a dog’s skin.
Systemic fungal infections
Ketoconazole is relatively inexpensive and widely available. For these reasons, vets prescribe it to treat systemic fungal infections, such as:
Aspergillosis
Blastomycosis
Coccidioidomycosis (valley fever)
Cryptococcosis
Histoplasmosis
Ketoconazole is not FDA approved for use in dogs. But it can still be prescribed to dogs off-label or extra-label, which is common in veterinary medicine.
There are other antifungal medications that are sometimes preferred over ketoconazole. While more expensive, itraconazole carries fewer side effects than ketoconazole. Fluconazole is similar to ketoconazole but preferred for fungal infections affecting the brain.
How is ketoconazole given to dogs, and what is the recommended dosage?
Your veterinarian will determine your dog’s ketoconazole dosage based on the type of fungal organism being treated and where the infection is located.
Does your dog need an MRI? If so, it’s important to know how much dog MRIs cost and ways to save money on these pricey scans.
Signs of fungi: From fever to skin sores, being able to recognize signs of a fungal infection in dogs can help you determine if your pet needs a trip to the vet.
Another antifungal to consider: Like ketoconazole, fluconazole treats a wide range of fungal infections Learn more about fluconazole for dogs here.
Ketoconazole is typically given to dogs once a day. But depending on the severity and type of the infection, ketoconazole may be given twice a day (every 12 hours).
The length of ketoconazole treatment can vary. For a Malassezia yeast infection, treatment may last for 2 to 4 weeks. But many fungal infections take several weeks or even months to resolve. In rare cases, dogs may need to remain on ketoconazole for a year or more.
Oral dosage
Oral ketoconazole only comes in 200 mg tablets. You may need to split up the tablets before giving your dog a dose. Nizoral is the most common brand-name version of ketoconazole, but there are many generic forms available.
Read more like this
Explore these related articles, suggested for readers like you.
Give oral ketoconazole to your dog with a meal. Taking ketoconazole with food — especially food that’s higher in fat, like cheese — helps the body absorb the medication. It can also reduce the likelihood of side effects.
Topical dosage
Topical ketoconazole comes in various forms, including:
Shampoos
Mousses
Sprays
Wipes
Ear washes
Creams
Concentrations of ketoconazole in topical products range from 0.1% up to 1.0%. These products are used to treat ear and skin infections caused by Malassezia and can sometimes help treat ringworm lesions. Your veterinarian will tell you how often to apply topical ketoconazole.
What should you do if your dog misses a dose of ketoconazole?
If you forget to give your dog a dose of ketoconazole and it’s only been an hour or two, you can still give them the dose. Here are general guidelines to consider if it’s been longer:
If your dog receives ketoconazole once every 24 hours and less than 12 hours have passed since the missed dose, give them the medication as soon as possible. Then, shift their medication schedule so that you’re giving them their doses at that time every day.
If your dog receives ketoconazole once every 24 hours and more than 12 hours have passed since the missed dose, wait until the following day to give them the medication.
If your dog receives the medication every 12 hours and more than 6-8 hours have passed since the missed dose, skip the missed dose and give them their next dose at the regular time.
In general, try to give your dog their doses of ketoconazole as close to the scheduled time as possible.
What are the common side effects of ketoconazole in dogs?
The most common side effects of ketoconazole in dogs are digestive issues. This may include:
Weight loss
What are the most serious risks of ketoconazole for dogs?
Ketoconazole can cause liver toxicity in dogs. While higher dosages can increase the risk of liver toxicity, even dogs taking lower dosages of ketoconazole can develop liver damage.
The most common signs of liver toxicity from ketoconazole in dogs include:
Loss of appetite
Vomiting
Diarrhea
Lethargy
Yellowing of the skin, gums, or whites of the eyes
Other less common but serious side effects of ketoconazole in dogs include:
Thrombocytopenia (low platelet count)
Ataxia (lack of balance when walking)
Cataracts, which is sometimes seen with long-term use
Behavioral changes
Lightening of the coat
Ketoconazole can also temporarily suppress steroid production by the adrenal glands.
And higher dosages of ketoconazole may contribute to Addison’s disease. Your dog may need to take a steroid like prednisone while being treated with keoconazole.
Unless necessary, avoid giving ketoconazole to dogs who are:
Pregnant
Nursing
Intended for breeding
Use ketoconazole products with care in households with cats. Cats are more susceptible to the medication’s side effects.
Does ketoconazole interact with any other dog medications?
Yes, ketoconazole can interact with many other pet medications. This does not mean they cannot be used together. But first discuss the benefits and risks of combining ketoconazole with other medications with your veterinarian. And be especially cautious about giving your dog ketoconazole alongside other medications that can lead to liver problems.
Some medications that can interact with ketoconazole are:
Antibiotics, such as cyclosporine, ciprofloxacin, and amitriptyline
Omeprazole (Prilosec)
Ondansetron (Zofran)
Warfarin
Frequently asked questions
Yes, ketoconazole shampoo is safe for dogs. But talk to your veterinarian before you start using it on your dog. They can tell you if this medicated shampoo is right for your pet.
Ketoconazole seems to lower cortisol levels after 1 month of treatment. Because of this, your dog’s cortisol levels should be tested in a veterinary office or animal hospital regularly if they’re taking ketoconazole long term.
Ketoconazole cream is available for dogs with a prescription from select veterinary pharmacies. If a vet prescribes your dog ketoconazole cream, ask for guidance on how much and how often to apply it.
The bottom line
Ketoconazole (Nizoral) is a common medication used to treat fungal infections in dogs, especially fungal infections on the skin. Other antifungal medications are sometimes preferred for more serious fungal infections. But the availability and lower cost of ketoconazole make it a common treatment choice.
Watch for signs of digestive upset in your dog once they start taking ketoconazole. Also, bear in mind that ketoconazole interacts with many pet medications. Make sure to discuss any questions or concerns you have about the medication with your veterinarian, especially if your dog needs to take ketoconazole for a long period of time.
Why trust our experts?
References
Boechat, J. S., et al. (2020). Canine sporotrichosis: Polyphasic taxonomy and antifungal susceptibility profiles of Sporothrix species in an endemic area in Brazil. Brazilian Journal of Microbiology.
Brooks, W. (2023). Allergies: Atopic dermatitis (airborne) in dogs and cats. Veterinary Partner.
Brooks, W. (2023). Ketoconazole (Nizoral). Veterinary Partner.
Budde, J. A., et al. (2023). Ketoconazole. Plumb’s Veterinary Drug Handbook, 10th Edition. Wiley-Blackwell.
Graybill, J. R., et al. (1997). Key issues concerning fungistatic versus fungicidal drugs. European Journal of Clinical Microbiology and Infectious Diseases.
Kukanich, B. (2008). A review of selected systemic antifungal drugs for use in dogs and cats. DVM360.
Lien, Y. H., et al. (2008). Use of ketoconazole to treat dogs with pituitary-dependent hyperadrenocorticism: 48 cases (1994–2007). Journal of the American Veterinary Medical Association.
Mayer, U. K., et al. (2008). Adverse effects of ketoconazole in dogs – A retrospective study. Veterinary Dermatology.
Rhimi, W., et al. (2020). Malassezia spp. yeasts of emerging concern in fungemia. Frontiers in Cellular and Infection Microbiology.
Shipstone, M. (2022). Antifungals for integumentary disease in animals. Merck Veterinary Manual.
Weber, M. J., et al. (1985). Treatment of systemic candidiasis in neutropenic dogs with ketoconazole. Experimental Hematology.
