Veterinarians use ketoconazole in dogs for selected fungal infections, including ringworm and Malassezia yeast infections. It has also been used to manage pituitary-dependent Cushing’s disease because it suppresses steroid production. These are distinct uses, and whether ketoconazole is appropriate depends on the diagnosis and the product available in your country. Oral treatment needs veterinary supervision because it can cause stomach upset, affect the liver and reproductive hormones, and interact with other medicines.
What conditions can ketoconazole treat in dogs?
Ketoconazole is an imidazole antifungal. Veterinary references describe its use against certain fungi and yeasts, but that does not mean it is the right treatment for every skin problem or fungal disease. A veterinarian should identify the likely cause and choose the medicine and formulation.
Ringworm (dermatophytosis)
Veterinarians may use oral ketoconazole for dermatophytosis, the fungal infection commonly called ringworm. The UK Veterinary Medicines Directorate’s leaflet for Fungiconazol 200 mg tablets specifically lists Microsporum canis, Microsporum gypseum and Trichophyton mentagrophytes. Those are indications for that named UK product, not a universal label for every ketoconazole medicine.
Ringworm treatment is generally continued until mycological cure is confirmed, for example by a negative fungal culture or PCR. The Merck Veterinary Manual says this can take at least four to six weeks; that is a minimum timeframe, not a fixed stopping date. Do not start human tablets or decide a dose or duration yourself.
#1 Best Overall
- Powerful Chlorhexidine Formula: Advanced ketoconazole shampoo with 1% ketoconazole and 2% chlorhexidine gluconate supports pets with stubborn skin concerns, offering effective antifungal dog shampoo and antimicrobial benefits.
- Antimicrobial Support: Nizoral's antimicrobial medicated dog shampoo for smelly dogs helps reduce irritation, itch, and odor while supporting healthier skin and coat comfort. Use 2-3 times per week as needed or as directed by your veterinarian.
- Medicated Relief for Irritated Skin: Nizoral s dog and cat shampoo with its soothing medicated formula helps calm itchy, irritated skin and ease discomfort without harsh additives. Gentle enough for regular use, it provides comforting relief.
- Ideal for Hot Spots, Odor, and Persistent Irritation: Targets problem areas as a hot spot shampoo for dogs, reducing odor and buildup while promoting cleaner, healthier skin perfect for pets needing a stronger medicated shampoo for dogs
- Gentle Care for Dogs and Cats: This gentle Nizoral chlorhexidine shampoo for dogs and cats is safe for multi-pet homes and works well as a cat wash or shampoo for dogs with itchy skin, providing a versatile option for overall coat maintenance.
Malassezia and other fungal infections
Veterinary references also describe ketoconazole use for Malassezia pachydermatis, a yeast associated with skin and ear disease in dogs. It has been used for some systemic fungal infections, including cryptococcosis and coccidioidomycosis. For systemic disease, however, other azole antifungals are generally preferred, so the choice depends on the organism, disease site and individual dog.
Pituitary-dependent Cushing’s disease
Ketoconazole suppresses the production of steroid hormones, including cortisol. Veterinarians have used it for canine pituitary-dependent hyperadrenocorticism, also called Cushing’s disease. This is an endocrine treatment—not treatment for a fungal infection—and requires veterinary monitoring.
Rank #2
- HELPS SUPPORT HEALTHY SKIN - With a wash and soaking of the coat for 5-10 minutes, our powerful ingredients work to help soothe red, scaly, greasy, or smelly skin that may cause your pet discomfort
- FAST ACTING – Works fast to soothe your pet's sensitive skin that may be affected by environmental stressors
- VET-RECOMMENDED – This pet shampoo is pH balanced for your pet's skin and is paraben and soap-free to promote overall skin and coat health without damaging detergents
- FOR DOGS AND CATS – Our cat and dog shampoo is intended for pets over 12 weeks of age. Use twice weekly until skin clears up, then once a week to help maintain skin health
- APPLICATION: This product is intended for topical use only. Read directions carefully before applying to your pet's coat. Test on a small area to avoid further sensitivity before using
How do topical ketoconazole products differ from tablets?
Topical products are applied to the skin or coat; they are not interchangeable with oral treatment. The appropriate product depends on the diagnosis and should be selected with a veterinarian. The UK Fungiconazol leaflet recommends combining systemic and topical treatment for dermatophytosis.
In the United States, a DailyMed label lists a pet shampoo containing ketoconazole 1% and chlorhexidine 2% for dogs and cats. The label expressly states that the product “has not been found by FDA to be safe and effective” and that the labeling “has not been approved by FDA.” It should not be described as FDA-approved. Read the DailyMed label.
Recommended Free Tools
Rank #3
- A HEALING CLEAN : Yes, it’s shampoo for dogs! Yes, it’s shampoo for cats! And yes, it’s shampoo that cleans & heals! It soothes irritated skin, providing itch relief for cats, & dogs. An effective shampoo for dogs with allergies & cats, it promotes a shiny coat, reduces inflammation, & helps heal hot spots. This cat & dog antibacterial shampoo also reduces smelly odors associated with bacteria & fungus. Basically, our cat & dog shampoo for yeast & itching is 16 ounces of a better clean routine.
- FROM THE INSIDE OUT: Made with a veterinary strength formula, our shampoo for dogs with itchy skin & cats is made with soothing aloe & without sulfates, parabens, phthalates, alcohol, & artificial colors. Our shampoo with chlorhexidine & ketoconazole for dogs & cats is a gentle, safe & effective way to help heal skin issues while keeping your pet comfortable & clean.
- THE PET, PET WASH: You know our cat & dog shampoo for sensitive skin provides relief for itchy skin, soothes irritated & inflamed skin, targets smelly odors, & promotes a shiny coat. But did you know that’s it’s the #1 chlorhexidine shampoo on Amazon*? Don’t wait to give your pet the healing wash they deserve. *Based on Stackline Atlas data (had to combine all grooming & other pet health supplies to capture entire market*L52W as of December 2024
- ON THE RIGHT SCENT: Not only does our medicated dog shampoo for itchy skin soothe irritation, promote a health coat & leave your pet feeling fresh & clean, it also has a light cucumber melon scent that helps with unpleasant odors from fungus & bacteria.
- THE HONEST DIFFERENCE: Our products are made with clean, science-backed ingredients for results you can trust, & with no fillers, artificial preservatives, colors, or flavors, you'll have no doubt your dog is getting the best. Proudly supporting pets in need nationwide & using recycled plastic in our packaging, there's also no doubt that we're committed to doing our best. -- All products are made in the U.S.A. | NASC Member Company
What side effects and risks should owners know about?
Stomach upset and other reported effects
Veterinary references describe inappetence or anorexia, vomiting, diarrhea, itching, hair loss and reversible lightening of the coat. The UK product information also lists apathy, neurological signs and hepatic toxicosis. Contact your veterinarian if your dog develops concerning signs during treatment; do not change or stop a prescribed course without veterinary advice unless you have been instructed to do so for a suspected serious reaction.
Liver injury and monitoring
Ketoconazole can increase liver enzymes and has been associated with liver injury. The UK product information advises close monitoring of liver function during long-term treatment and says to stop treatment immediately if signs suggest liver dysfunction. Ask the prescribing veterinarian what monitoring is appropriate for your dog. Human ketoconazole monitoring guidance is not a substitute for canine prescribing advice.
Rank #4
- Supports healthy skin for animals
- Formulated for dogs, cats and horses
- Supports restoring dry, damaged skin
- Made in the USA.
Hormones, pregnancy and breeding
The UK product leaflet says ketoconazole suppresses testosterone and increases progesterone, and may affect breeding effectiveness in male dogs during treatment and for some weeks afterward. Tell the veterinarian if your dog is intended for breeding.
Safety has not been established in pregnant or lactating dogs. The UK product information does not recommend use during pregnancy and reports teratogenic and embryotoxic effects in laboratory animals. Merck also advises avoiding ketoconazole in pregnant animals where safety studies have not been conducted. Discuss pregnancy or nursing status before treatment.
Best Value
- Helps support healthy skin in pets
- Degreases the skin and coat as it gently cleans
- For dogs, cats and horses
- Has a pleasent smell
- Manufactured using GMP, and the highest quality ingredients
Medicine interactions and absorption
Ketoconazole is best absorbed in an acidic environment. Merck and the UK product information warn against giving it alongside antacids or H2-receptor antagonists. Give the veterinarian a complete list of your dog’s medicines and supplements so they can assess interactions and advise what to do.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What matters when choosing a treatment?
There is no universal “best antifungal” for dogs. The decision depends on the organism and, where possible, susceptibility; whether the infection is limited to the skin or is systemic; liver health; other medicines; reproductive status; and the products authorized and available locally. Merck describes itraconazole and terbinafine as alternatives for canine dermatophytosis, and says itraconazole and fluconazole are generally preferred to other imidazoles for systemic fungal infections.
For ringworm, treatment also includes controlling environmental contamination. Spores can survive for long periods, and the listed dermatophytes can spread to people. Follow your veterinarian’s cleaning advice; the UK leaflet recommends frequent vacuuming, cleaning grooming equipment and removing items that cannot be disinfected. Wash your hands and use good hygiene when handling an affected dog.
Quick Recap
When to call the veterinarian
- Before using ketoconazole, to confirm the diagnosis, product and treatment plan.
- Promptly if your dog develops vomiting, diarrhea, loss of appetite, unusual tiredness, neurological signs, or possible liver-related illness during treatment.
- Before treatment if your dog is pregnant, nursing, intended for breeding, has liver problems, or takes other medicines or supplements.
- To confirm when ringworm treatment can end; skin looking better alone does not establish mycological cure.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →
