September 1, 2009 "Ask Seth"

My new dog has been diagnosed with ringworm. What exactly is ringworm in dogs and is it treatable?

Dear Seth,

My new dog has been diagnosed with ringworm. What exactly is ringworm and is it treatable?



Despite the name, ringworm is a fungus that causes circular lesions. It is important to know that ringworm can easily spread between pets and humans. There are many treatment options that will usually clear up the fungal infection up in a few weeks.

Ringworm is a skin condition that occurs approximately 7-10 days after an animal comes in contact with the fungus. Ringworm lives in hair follicles, and causes the hair to become brittle and fall out. The disease looks like a circle with raised edges and can include crusty skin, scaling and even redness. It is most commonly seen on the head, ears, tails and front paws.

Ringworm can be transmitted between dogs, cats and humans. Children are more susceptible than adults. The fungus produces spores that can get into bedding and cause an infection, so wash all exposed garments in bleach and water. If you think you have a ringworm infection, see your family doctor.

Treatment is usually based on the use of anti-fungal shampoos. These shampoos will help kill the spores that cause the infection and are to be used as directed. It is important to allow the shampoo to sit on the dog as long as recommended. Follow the directions on the bottle.

In some cases, anti-fungal medications can be used. These are given orally and for a longer period of time (approx. 30 days). I have used these with great success when given with food. Once the infection has cleared up, it is necessary to clean all exposed areas and fabric with bleach to help prevent re-infection.

Seth Mayersohn, CVT

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