Ringworm, more correctly called Dermatophytosis, actually has nothing to do with worms. It’s name came from the characteristic raised ring which, in humans, looks like a worm lodged underneath the skin.
Actually, it is a type of fungal infection. In Pets it most commonly affects the skin, fur, and nails. Cats are more prone to contracting ringworm than dogs or other species. They also shed larger numbers of fungal spores when they are infected.
The most common signs of ringworm infection in Pets are hair loss, itchiness, flaky skin, and brittle or misshapen nails. Unfortunately, the symptoms of ringworm are similar to almost every dermatological condition we see as veterinarians, which makes it tricky to diagnose.
It is important to note that cats can also be asymptomatic carriers, meaning that while they look perfectly normal themselves, they can still be a source of infection for other individuals in the household.
When diagnosing ringworm, the most commonly used test involves plucking hairs from affected parts of the body, pushing them into a special type of growth medium. This method can take up to three weeks to see what grows. Some veterinarians will also use a black light to identify which parts of the body are potentially harboring ringworm organisms, as some types are fluorescent. However, examination by black light alone cannot definitively diagnose or rule out ringworm.
In difficult cases, a skin biopsy might be necessary to reach a definitive diagnosis. Something called a toothbrush test, essentially brushing a pet’s fur with a toothbrush and then poking the bristles into a fungal growth medium, is a good way to screen potential asymptomatic carriers.
Handling Contagious Pets & Treatment
Treating ringworm is even more difficult than diagnosing it. Mild to moderate cases may respond to medicated baths, lotions or dips. Shaving pets with long fur helps medications reach the skin and greatly reduces the number of fungal spores present. In severe cases, oral anti-fungal drugs could be necessary.
Because ringworm is so contagious, animals undergoing treatment need to be isolated and owners should decontaminate the parts of the home where infected critters have spent time. Vacuum floors, rugs and upholstery thoroughly, and wash everything possible in hot water and dry on a hot setting. A one part bleach to thirty parts water solution will kill the fungus on hard surfaces that can handle such treatment. As always, wash your hands thoroughly after handling any pet, especially if it might have ringworm.