Cat Health
Itraconazole for Cats: An FDA-Approved Medication for Ringworm
Key takeaways:
Itraconazole (Sporonox) is an antifungal medication used to treat cats. It’s the only FDA-approved treatment for ringworm in cats, and it can also treat other fungal infections.
Itraconazole has a low risk of side effects in healthy cats. If your cat does experience side effects, they may include lack of appetite, vomiting, and diarrhea.
The medication is most commonly given to cats in a liquid form, once or twice a day, for several weeks to months.
If your cat was recently diagnosed with ringworm or another fungal infection, your veterinarian may have prescribed them itraconazole (Sporanox).
Although multiple medications can treat ringworm, only itraconazole is FDA approved for use in cats. This specific brand and formulation has been tested by the FDA, and it is proven to be safe and effective for cats. It can also be used to treat several other fungal infections.
Common names | Itraconazole (Sporanox, Itrafungol) |
What it treats | Ringworm and other fungal infections |
How it comes (forms) | Liquid suspension, tablets, capsules |
Common side effects | Decreased appetite, nausea, vomiting, diarrhea |
Itraconazole is an antifungal medication that is used to treat a variety of fungal infections in cats.
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The medication disrupts fungal cell membranes, causing fungal cells to die. This eliminates the fungal infection, allowing your cat to heal.
As mentioned, itraconazole is FDA approved to treat ringworm in cats. While the name “ringworm” might suggest that this common feline skin disease is caused by worms, it’s actually a fungal infection. The infection is named for the ring-shaped areas of hair loss that often develop in infected cats.
Itraconazole can also treat other fungal infections, including:
Candidiasis
Coccidiomycosis (Valley Fever)
Malassezia infection
Pythiosis
Sporotrichosis
Itraconazole for cats is most commonly supplied as a liquid suspension. This suspension is given by mouth, allowing the medication to distribute throughout your cat’s body. While capsules and tablets are also available, they can be difficult to give to cats.
Your veterinarian will determine your cat's dosage, which will depend on your cat’s weight and the condition being treated. Most cats will need to be given itraconazole once or twice daily, for a period of weeks to months. Treatment can vary though, so it’s important to follow the specific instructions provided by your veterinarian.
Itraconazole is well tolerated by most cats. The risk of side effects appears to be lower with itraconazole than with other common antifungal medications.
The most common side effect in cats is gastrointestinal issues. Gastrointestinal side effects related to itraconazole may include:
Decreased appetite
Nausea
Vomiting
Diarrhea
If your cat has any of these side effects while taking itraconazole, contact your veterinarian. They may be able to recommend steps you can take to minimize your cat’s side effects. Or they may recommend a different medication.
Itraconazole can affect liver function in cats. While this is very rare, it’s possible and can be serious. Therefore, many veterinarians avoid prescribing itraconazole to cats who have liver disease. Itraconazole should also not be given to cats who have kidney disease. Your veterinarian may recommend blood tests to check liver and kidney function before your cat starts treatment with itraconazole.
Itraconazole should not be given to pregnant or nursing cats. The medication may cause miscarriage and/or birth defects.
Itraconazole works similarly to many other medications. If your cat takes multiple medications that work similarly, the risk of side effects increases. Other medication interactions may also occur with itraconazole.
Talk to your veterinarian before combining itraconazole with any of the following medications:
Alprazolam (Xanax)
Antacids
Cyclosporine
Diazepam
Digoxin
Glipizide
Ketoconazole
Midazolam
Phenobarbital
Phenytoin
Quinidine
Rifampin
Warfarin
Never give your cat multiple medications at once unless your veterinarian has instructed you to do so. And be sure that your veterinarian is familiar with any medications your cat takes. This includes not only prescription medications, but also over-the-counter medications and supplements. This will help your veterinarian reduce the risk of interactions.
If your cat misses a dose of itraconazole, give them the missed dose as soon as you remember. If it is almost time for your cat’s next dose, skip the missed one and give them the next dose at the scheduled time. Do not give your cat a double dose of itraconazole.
Although fungal infections can be scary, itraconazole is a safe and effective treatment option for cats. It’s FDA approved to treat ringworm in cats, and it can be used for a number of other infections.
Most often, your veterinarian will prescribe itraconazole as a liquid for your cat. Follow your veterinarian’s dosage instructions, and watch for side effects. If you have any concerns, reach out to your veterinary team.
Brister, J. (2020). Aspergillosis in cats. Veterinary Partner.
Brooks, W. (2023). Itraconazole (Sporonox). Veterinary Partner.
Centocor Ortho Biotech Products, L.P. (2011). Sporanox (itraconazole) oral solution [package insert].
Cornell University College of Veterinary Medicine. (2021). Coccidioidomycosis.
Cornell University College of Veterinary Medicine. (2021). Cryptococcosis.
Cornell University College of Veterinary Medicine. (2021). Histoplasmosis.
Gull, T. (2023). Blastomycosis in animals. Merck Veterinary Manual.
Shipstone, M. (2022). Antifungals for integumentary disease in animals. Merck Veterinary Manual.
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