The number one site for veterinary news and information
By Andrew Montague M.V.B. Cert. Small Animal Medicine
Home Page: Cats: Skin: Ringworm
Ringworm in the Cat
Posted 16th June, 2000
Despite its colourful name, ringworm has nothing to do with worms. It's a fungal infection of the skin and it's common in cats. Kittens are the most common patients but adult cats can also be affected.
Ringworm is highly contagious. As well as spreading from cat to cat it can spread from cats to humans. I would advise any cat owner that develops ringworm to have their cat examined by a veterinary surgeon even if there are no obvious lesions on their cat. Dogs too can get ringworm, but this is less common than in the cat.
The classical ringworm lesion is a circular patch ('ring') of hair loss, but ringworm can show up in many different forms. There may be crusts, scaly skin, broken hairs and changes in skin colour. Some infected cats have no visible lesions. These cats can be a hidden source of ringworm spreading the infection to other cats and to their owners.
" ...it can spread from cats to humans. "
Vets often diagnose ringworm based on the appearance of the skin lesions, but confirmatory tests are usually required. A Wood's lamp is an ultraviolet lamp that can detect the presence of ringworm. When viewed with a Wood's lamp some lesions glow an apple green colour. Unfortunately, this does not happen in all cases. If ringworm is suspected, but not confirmed with a Wood's lamp, further tests are required. To confirm the presence of ringworm, hair samples are cultured or viewed under a microscope.
Antifungal drugs prescribed by a vet are the standard treatment for ringworm. Most cats respond well to treatment although it can take weeks or months to cure the infection. Cats undergoing treatment need frequent monitoring by a vet as these drugs can occasionally cause side-effects. It's a good idea to continue treating your cat for two weeks after all clinical signs have disappeared.
Topical treatments such as creams or washes can be used, but they are not as effective in cats as they are in humans. The cat's coat prevents the treatment penetrating to the lesions and cats will often lick off applied creams.
Cat hairs can spread ringworm. Thorough hoovering of the house can reduce the number of infective hairs limiting the spread of infection. Cat combs and brushes should be disinfected regularly. Some researchers advise clipping the cat's coat but this has not been proven to be beneficial.
Ringworm can be difficult to get under control due to its contagious nature. It's especially difficult to control in multi-cat households where the infection can spread from cat to cat to cat. However, treatment of all affected cats for sufficient periods of time combined with scrupulous hygiene should allow this condition to be managed in most situations.