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Ringworm and Your Pets
M Duffy Jones, DVM posted:
Is ringworm really a worm? No. Actually, ringworm is a group fungus that feeds on dead skin. In humans, it presents as a very distinctive circular lesion in the skin. The lesion is typically red and raised and scaly on the edges, while the center starts to heal.

In animals, these lesions tend to be scaly and vary in appearance. They can look similar to many other types of lesions, which can make reaching the proper diagnosis difficult.

Ringworm Facts

1. Ringworm fungi are very resilient in the environment. But they require a broken or scratched skin site in order to produce spores and spread from one host to another.
2. Although ringworm may cause some unsightly skin lesions, in general, it does not cause too extensive of a disease in its hosts.
3. Some animals are carriers, meaning they never show any signs of ringworm. But they are constantly dropping spores and potentially infecting others.
4. Some people are more susceptible to these ringworm fungi than others. The young, elderly, or immune-compromised people are more prone to pick up a ringworm infection.

How Ringworm is Diagnosed

- Wood's Light Examination: This is a very simple test, which can be done in your vet's office. When held near the lesion, the Wood's lamp's ultraviolet light causes the ringworm to fluoresce green. Unfortunately, this exam will catch only about 50% of ringworm infections, because half of these infections will not turn green under the light.
- Microscopic Examination: Sometimes the fungal spores are visible on a host's hair under a microscope. But they are difficult to see. So they can be missed in about half of the cases with this exam, as well.
- Fungal Culture: For this culture, a sample of hair is plucked from the skin and placed in a dish to allow any present fungi to grow. This test makes it possible for your vet to tell if there is ringworm present and exactly which fungi are causing the problem.
- Skin Biopsy: Sometimes a ringworm infection is so deep in the skin that the only way it can be found is by removing a small piece of skin or tissue and observing it microscopically for any fungi.

How Ringworm is Treated

Pets with ringworm need to be isolated during treatment. Otherwise, they will continue shedding fungal spores in your home. Disinfecting the environment is also important during this time.

In my practice, I typically treat pets with oral medication and dips and baths. Many times the type of treatment your vet will use depends on your pet's age and any other medical problems your pet might have.

If you are concerned that your pet has ringworm, make an appointment with your vet. He or she can decide what tests to run and which treatment will work best for your pet.


William Draper, DVM, better known as "Dr. Will," is a well-known small animal practitioner in the Atlanta, GA area. He grew up in Inglewood,...More

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