Fungi are yeasts and moulds (and mushrooms, smuts and rusts but these do not cause infections in animals). In the great scheme of life, fungi are responsible for decomposition. They break down organic material. In some circumstances however, usually associated with an underlying malfunction of the immune system, fungi cause illness.
Fungal disease is a common cause of skin disease in cats, especially longhaired cats.
This is overwhelmingly the most common fungal infection to afflict cats and dogs. In otherwise healthy individuals with efficient immune systems, antibodies eventually overcome the infection. Medical treatment remains necessary because of the high risk of spread to other animals and to us during the weeks it takes for the immune system to respond. In longhaired cats the infection is so pervasive it can be extremely difficult to eliminate completely. Ringworm is diagnosed by clinical signs, fungal culture and, for the most common form of the infection (Microsporum canis) fluorescence under ultra violet light. We treat with topical imidazole group antifungals (miconozole, ketoconazole etc) and oral antibiotics (griseofulvin) for at least one month. Malassezia shampoo is routinely used.