Ringworm is a skin disease which can affect dogs, cats, human and other animals.  The disease is caused by a fungus (not a worm!) which lives on the skin and hairs.  Infection is acquired by direct contact with infected animals or through contact with contaminated inanimate objects such as bedding, feeding bowls or grooming tools.  Ringworm occurs much more commonly in cats than in dogs. The clinical signs of ringworm can be quite varied.  In the dog there may be circular areas of baldness which may be grey or reddened  with scaling or crusting of the skin.  The signs may be confined to specific areas such as the head or forelimbs or may be more widespread.  In the cat the lesions may appear as circular areas of grey scaling giving a “cigarette ash” appearance.  Because the clinical signs associated with ringworm can be quite varied some diagnostic aids may be needed in the investigation of a suspect case.  Some types of ringworm will flouresce bright apple green when examined under an ultra violet light.  In many cases we will examine hairs plucked from a lesion under the microscope or submit them to our lab for fungal culture. Some cats may be asymptotic carriers of the fungus, i.e. they can pass it on to to other animals and people but show no clinical signs of the disease.

Ringworm is a zoonotic infection which means it can be passed from animals to people.  Whether or not someone catches ringworm from an infected animal depends on many factors such as their age and immune status.  In general children are more susceptible than adults and females more succeptible than males. Some cases of ringworm are self-limiting but because of the human health risk all cases should be treated.

Treatment can last for several weeks and will include some or all of the following:

  • An antifungal oral medication or wash for your pet
  • Topical antifungal creams
  • Clipping the hair around the affected areas or clipping the hair all over the body.  This is especially important in long haired animals.
  • Examination and treatment of in  contact animals
  • Destroying of all contaminated materials such as bedding and thorough disinfection of feeding bowls and grooming tools is another important step in controlling the disease.

Because ringworm is a zoonosis, owners (especially children) should limit contact with infected animals as much as possible. We recommend washing your hands with a disinfectant soap after handling an infected animal, or even wearing rubber gloves. If you are worried that you have contracted ringworm from your pet then you should seek the advice of your doctor or pharmacist. Remember: ringworm in people is generally a mild infection and is easily treated.