Antifungals Dogs

Ketoconazole for dogs

Treats fungal infections. Vets sometimes use it to lower the dose needed of cyclosporine. [1]

Last reviewed: October 2026 · 2 sources · see sources

Quick answerKetoconazole (ketoconazole (oral)) is a prescription medicine for dogs. An older antifungal that blocks fungal membrane building. The most common side effects: low appetite, vomiting, diarrhea and liver injury.

Key facts

Generic nameKetoconazole (oral)
Common brand namesNizoral
Used inDogs
TypeAntifungals
Prescription?Prescription
Typical US priceNot listed (no reliable public source)

What it's used for

Treats fungal infections. Vets sometimes use it to lower the dose needed of cyclosporine. [1]

How it works

An older antifungal that blocks fungal membrane building. [1]

Side effects and cautions

Common side effects: Low appetite, vomiting, diarrhea and liver injury. It can also lower cortisol levels. [1]

Use with care: Used with great caution in cats because of side effects. Not for pregnant pets except in serious infections. [1]

Call your vet right away if your pet has trouble breathing, facial swelling, hives, collapse, or any side effect that is severe or getting worse.

About dosingDosing is your vet's call. We don't list doses because the right amount depends on your pet's weight, age, health and other medicines. Don't change a dose or stop a medicine without asking your vet, and never give a pet medicine meant for people unless your vet tells you to [2].

What it costs

We don't list a price for this one because we couldn't find a reliable public source. Ask your vet or pharmacy for a quote; prices depend on your pet's size, the dose and where you fill it.

Ketoconazole FAQ

What is Ketoconazole used for in dogs?

Treats fungal infections. Vets sometimes use it to lower the dose needed of cyclosporine.

What are the side effects of Ketoconazole?

Low appetite, vomiting, diarrhea and liver injury. It can also lower cortisol levels.

Does Ketoconazole need a prescription?

Yes. It needs a prescription from a veterinarian.

How much Ketoconazole should I give my pet?

Only your veterinarian can tell you. The right dose depends on your pet's weight, health and other medicines, so we don't list doses. Never give a pet a medicine prescribed for a person or another animal without asking your vet.

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This page is general information for pet owners, not veterinary advice. Talk to your vet about your own pet.

Sources (2) — tap to show
  1. VCA Animal Hospitals – Ketoconazole (oral) (veterinary drug handout)
  2. FDA – Frequently asked questions about animal drugs