Pet Dermatophytosis (Ringworm)
Download our handout on Dermatophytosis.
Dermatophytosis is a fungal infection that affects the hair, skin, and sometimes nails. In spite of its name, no worms are associated with this problem. The most common sources of these fungi are other infected pets, a contaminated environment, rodents, and soil. Animals can sometimes act as carriers of these fungi and have no visible lesions, and some fungi can also live in the environment for years and be very difficult to remove. Visible infection in a pet may occur due to skin abrasions or a lowered immune function, as well as stress contributing to clinical infection.
Infected pets can show clinical signs such as hair loss, broken hairs, scaling (dandruff), and darkened skin color. Signs can be subtle and look like other diseases. Other symptoms can include red bumps, itching, crusting, and occasionally exudate. When nails are infected, they can become brittle and deformed, and then break easily or fall off.
Diagnosis may be difficult and may sometimes take several repeated tests with cultures that can take up to 4 weeks to grow. Animals that are suspected carriers must be evaluated by special techniques to obtain samples for fungal culture.
