Ringworm: It's Not What You Think!

Despite its name, many pet parents are surprised to find that ringworm isn’t a worm—instead, it's a skin disease caused by a fungus.

Because the lesions are often circular, it was once thought to be caused by a worm curling up in the tissue, but this disease actually has nothing to do with worms at all!

Ringworm, also known as dermatophytosis, is a fungal infection in the superficial layer of the skin, hair and nails. The fungi that cause "ringworm" live in hair follicles and cause the hair shafts to break off at the skin line, resulting in round patches of hair loss. As the fungus multiplies, the lesions may become irregularly shaped and spread over the body.

Other symptoms of ringworm may include:

  • Poor hair coat
  • Dandruff
  • Reddened skin
  • Itchiness


It's important to note that many other skin diseases may have these same symptoms. In many cases, a pet examined for ringworm will actually be diagnosed with pyoderma, a bacterial infection of the skin.

Though it isn't common, ringworm is especially important to treat because it's infectious to dogs, cats and humans! If your child has ringworm, s/he may have acquired it from your pet, another child, an object, or the soil - and your pet may have acquired it from your child, another human, another pet, etc.

Adult humans are usually resistant to infection unless there's a break in the skin, but children are quite susceptible. If you or any members of your family have suspicious skin lesions, you should see a physician. While it requires a physician's diagnosis, the infection itself is generally easily treated.

For your pets, a veterinarian can diagnose ringworm using various methods, including identifying the lesions on the skin, examination of the hair under a microscope, fluorescence of infected hairs under ultraviolet light, or culturing of the hair. Treatment depends on the severity of the infection, how many pets are involved, if there are children in the household and how difficult it will be to disinfect your pet’s environment. Treatments generally entail either a shampoo or ointment, though some cases require oral medications to completely clear.

If you have any questions about ringworm or suspect your pet might be infected, give us a call or fill out our online form for an appointment.


This blog post originally appeared on The Drake Center

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