RINGWORM (DERMATOPHYTOSIS) Ringworm is the most common fungal infection of dogs and cats in the world. The incidence is three times higher in cats than in dogs and prevails in warm, humid climates. Ringworm, or Dermatophytosis, is an infection of the hair and hair follicles caused by certain types of Fungi termed Dermatophytes. In cats, over 90 percent of the cases are caused by a Fungus called Microsporum canis. These Fungi live on “Keratin”, which is a product found in the superficial layers of the skin, hair, and nails.
Ringworm is easily spread to other animals and people. Children and young animals are most susceptible. The classic Ringworm lesion looks like a circular patch of skin with either no hair or broken hairs. The edges of the lesion are generally red, scaly, and crusty. Longhaired cats, less than a year old in multi-cat environments, are at highest risk. Ringworm is spread by contact with an infected cat, infected hairs, or skins scales shed into the environment.
Pets with Ringworm usually have lesions on their heads and/or faces, although lesions on other body parts may occur.
(NOTE: Some cats with Ringworm are “healthy carriers”. They carry and spread the infection but show no signs themselves.)
DIAGNOSIS
1. A fungal culture is the most reliable way to diagnose Ringworm. Infected hairs and scales are “plucked” from the edges of the lesion and sent to the lab. They are grown in a special medium that changes color in positive cases.
2. A woods lamp is an ultraviolet light under which infected hairs may fluoresce a yellowish green color. It can take up to five minutes for the infected hairs to fluoresce and those that do should be cultured to confirm the diagnosis.
3. A “skin scraping” examined under the microscope for fungal elements also aids initial diagnosis.
TREATMENT
To get rid of this fungus completely can take three to four months. It requires patience and a lot of work. Exact treatment depends on the extent of infection and number of animals involved. Minor skin lesions may heal with topical anti-fungal creams, but in most cases, a combination of oral and topical anti-fungal medications are necessary for complete healing.
Trimming hair from small-localized lesions with scissors promotes healing (disinfect the scissors with bleach between lesions to avoid spreading the infection and don’t use clippers to remove the hair because they are too hard to disinfect.) For pets with lesions spread all over the body, clipping the hair is not recommended because that actually spreads the infection. Infected pets should be isolated. Owners can stop treating when fungal cultures generate negative results.
ENVIRONMENT CLEAN UP
Cleaning up the contaminated environment is extensive and costly. If possible, dispose of all pets bedding, brushes, blankets, scratching posts, etc.
Contaminated items you can’t dispose of must be disinfected.
To disinfect:
• Wash in a solution of hot water and iodine soap, then soak them in the same solution for one hour.
• Rinse them with a solution of 1 part chlorine bleach to 10 parts water.
• Air-dry them in sunlight.
Also:
• Dry clean drapes
• Steam clean carpets
• Clean floors and walls with chlorine bleach
• Vacuum and disinfect all heating and cooling vents
• Change air filters weekly
• Also disinfect your pet’s carrier and your car or van and cat flaps.
• Vacuum your home daily
• Clean pet’s cage daily
(NOTE: Be sure to wear rubber gloves and wash your hands well to avoid spreading Ringworm to yourself and/or other family members. A Ringworm Vaccine is available but is not routinely recommended.)
