Ketoconazole is an antifungal medication from the azole class of drugs, commonly used in veterinary medicine to treat a variety of fungal infections. It works by inhibiting the growth of fungi, making it effective in treating conditions like ringworm, blastomycosis, and histoplasmosis in pets. Ketoconazole is typically prescribed for dogs and cats when topical treatments are insufficient or when the infection is systemic.