Ringworm or dermatophytosis in cat is a fungal infection that affects the hairs, skin, and nails. It is caused by the Microsporum and Trichophyton species of the dermatophyte group. Dermatophytes feed on the nutrients found in the keratin material in hairs, nails, and skin. Microsporum canis (M. canis) is the most common cause of cat dermatophytosis and causes more than 90% of the cases.

- Susceptibility to Dermatophyte Spores

Dermatophytes produce spores during the infectious stage. When susceptible cats are exposed to fungal spores, they can develop dermatophytosis easily. Susceptible cats include those that are very young, particularly those cats that are less than a year old; cats that are old; and cats that are immunocompromised that may be caused by malnourishment, stress, illness, and diseases.

- Mode of Transmission

Spores can be transmitted through direct contact to an infected animal or person. They can also be transmitted through an indirect manner such as exposure of a cat to a contaminated environment or thing, because spores are found in the hairs of cat and they can also be found to areas where an infected cat usually stays. Cats can also acquire the dermatophyte spores from contaminated soil because spores can thrive in soil that has enough nutrients.

- Symptoms

The symptoms of dermatophytosis may manifest 10-14 days after exposure to the fungal spores. The number of fungal spores before it causes dermatophytosis is not known. Here are common symptoms of cat dermatophytosis:

1) Dry and scaly lesion, usually pale at the center.

2) Bald spots or patch may occur because hairs on the affected site fall off easily.

3) Inflammation and itchiness may also occur.

- Diagnostic Exam

1) Direct visualization of appearance of the ringworm can be done but it is not an accurate examination because the symptom may be caused by another disease or illness.

2) Examination of the hairs or skin cells of a cat using a microscope can also be done to detect the presence of fungal spores.

3) Examination of hair using an ultraviolet light (Wood's lamp).

4) Culture of hair pulled from an infected site can also be done to check for fungal growth.

- Treatment and Prevention

1) Systemic oral therapy is the most effective drug for dermatophytosis, example include griseofulvin and itraconazole.

2) Topical therapy such as lime sulfur solution, miconazole shampoo, and enilconazole solution are used to prevent environmental contamination.

3) While your cat is undergoing treatment, it is advisable to perform body clipping of long hairs to potentiate the action of topical anti-fungal treatment.

4) It is important to do environmental decontamination using disinfectant solution such as bleach (1:10 to 1:100 solution mixed in water). This will help to eliminate fungal spores to the place where your cat usually stays, especially their home environment. This will help you to avoid reinfection and spread of the fungal spores to your other pets and to household members.

5) When your cat has dermatophytosis, you should isolate them from other pets to avoid transmission of the dermatophyte spores.

6) Keep the cat's home clean and moist-free because fungal spores can thrive in such areas.