Animal Hospital
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Dedicated staff
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Hours of Operation:

Monday: 8:30 a.m.-7 p.m.
Tuesday: 8:30 a.m.-7 p.m.
Wednesday: 8:30 a.m.-5 p.m.
Thursday: 8:30 a.m.-7 p.m.
Friday: 8:30 a.m.-7 p.m.
Saturday: 8:30 a.m.-2 p.m.
Sunday: Closed

Ringworm: Not really a worm at all

Recently I read an article in this paper that the Town of Brookhaven Animal Shelter had an outbreak of ringworm and temporarily had to suspend adoptions until affected animals were treated and the facility was disinfected. What is ringworm? How do pets get it? What is the risk to humans?

Believe it or not, ringworm is not caused by a worm at all, but rather by a superficial fungal skin infection. The reason it got the name ringworm is that the fungi that cause the infection cause areas of circular alopecia, or hair loss. The circular shape led people to assume the infection was caused by a worm migrating outward from the center.

What really happens is the fungus infects the hair shaft and skin around it to cause the hair to fall out. In order to continue to replicate, the fungus needs both the hair and skin causing a bald spot to appear and increase in circumference. Most times the area affected does not itch but sometimes it can become secondarily infected with bacteria that normally live on the skin.

Ringworm is primarily a problem in cats but can also be seen in dogs and humans as well as other mammals. It has been estimated that approximately 10 percent of cats — whether they actually have evidence of ringworm or not — carry the fungi on their hair and skin. This can be a problem if there are other pets in the household as the original carrier may not even show typical signs of the rash.

Certain breeds of cats such as Persians can be predisposed genetically to getting the disease but we primarily worry about dogs and cats that have a compromised immune system. Dogs and cats that live in shelter-type facilities, as well as those that are stray or feral before entering the shelter are most at risk. These animals tend to be malnourished, many times are burdened with both internal (intestinal worms and other parasites) and external (fleas and ticks) parasites, and are under tremendous emotional stress. This can temporarily compromise the immune system. That, in combination with close contact, can cause an outbreak to rapidly spread.

Ringworm is diagnosed through testing that can sometimes be done right in your vet's office. If your veterinarian is suspicious of ringworm after examining your pet he or she may shine a Wood's lamp — basically a small medical-grade black light — on the rash. Some species of fungi that cause ringworm fluoresce and the diagnosis is made immediately.

Now, the test is only about 35 percent accurate so if the rash does not fluoresce you still could have ringworm. Luckily, there is a test called a dermatophyte test medium plate. All the ringworm fungi produce certain waste products as they grow and that causes the DTM plate to change color. Usually the color change will occur within five to 10 days after placing a hair sample from a contaminated area on it. If a color change occurs the test is positive. If not, whatever is causing the rash or hair loss is something else.

If ringworm is diagnosed it is treated by a combination of oral medication, clipping the hair on affected areas and special baths. It can take months to clear an infection in an affected animal so be patient and persistent. Environment control and cleanup is important. What this means is not only do all the other pets in the household have to be treated — even if they do not show signs of disease — but all the bedding has to be treated as well.

Ringworm can affect humans. A circular rash usually forms on the skin, and diagnosis is by a human physician. If you have a dog or cat that was diagnosed with ringworm or recently adopted a pet — even if no rash is seen — and develop a rash please see your physician immediately.

Remember this: ringworm is a very treatable skin condition in both pets and humans so don't stop adopting. This will be cleared up in no time and these beautiful creatures need homes.

Dr. Kearns has been in practice for 14 years and is pictured with his son, Matthew, his dog, Jasmine and his cat, The One Eyed Guy.

Matthew Kearns, DVM