Ringworm in Cats

Ringworm in Cats

What is ringworm?

Despite the name, ringworm is not a type of worm like tapeworm or roundworm but instead it is a form of highly contagious fungal infection. The medical term for ringworm infection is dermatophytosis, which is spread by fungi called dermatophytes, the most common being Microsporum canis (M canis) accounting for about 90% of all cases, and which can be passed between cats, dogs and humans. There are other less common forms that are contracted through infected wild rodents or rarely, through garden soil.

How do cats become infected?

This can happen by direct contact with an already infected animal, or by exposure to items that are shared between your cats and which could attract contaminated hairs or particles of skin, such as bedding, grooming brushes and combs, or even your furniture and carpets. The fungal spores are very resistant, and without any treatment they can remain infectious for up to two years, attaching themselves to the skin or hair, and although it is not always the case, it does seem to be more common in younger cats that may have less efficient immune systems.

What does it look like?

The signs vary especially if the spores are lying dormant, as they are not visible to the naked eye. Some cats display signs of serious dermatitis, and some show no visible symptoms at all to begin with, although the most common signs are small circular lesions causing an inflamed, scaly patch, usually about the size of a 1p coin, with the surrounding hair appearing damaged. The most commonly affected areas are the head, ears or paws, although these could also be an indication of other feline skin diseases such as a flea or other pest-related allergy, dermatitis triggered by something else, or possibly feline acne.If you do suspect that your cat may have ringworm, you should take sensible precautions until you know either way - don't let any of your cats go outdoors (to avoid causing a local epidemic) and ensure that none of your human household has contact with anyone else who has pets. Ideally, you should not have direct contact with any other people until you have had it confirmed either way, as it is so highly contagious.

How can I confirm if my cat has ringworm?

The only way is to take the cat to the Vet as soon as possible in order for them to conduct some tests, as they will not be able to know for sure just by looking at it. Probably the first thing your Vet will do is to use an ultraviolet Wood's Lamp in a darkened room, as the infected hairs may show a florescent green colour. However, this test is not 100% conclusive but may provide an indicator to the hairs that should be isolated for further microscopic examination and fungal culture tests, the latter being the most reliable method of confirming an infestation.

What should I do if the test result is positive?

If you have only one cat, the infection will be relatively simple to contain, but if you have more than one cat, all the others should also be tested, as the chances that they may have it too are quite likely. Although ringworm will usually resolve itself eventually in the case of otherwise healthy cats, a lot of damage could be done in the meantime by spreading it to other pets as well as to humans. Your Vet will prescribe daily administration of both oral medicine and a treatment to be applied directly to the hair and skin, which should resolve the problem within a couple of months. It is important to carry out your Vet's instructions to the letter in order to minimise the risk of spreading the disease, and you should also only administer medication specially formulated for animals. You should ask for special advice if you have any pregnant female cats or young kittens. Your Vet will also advise wearing gloves and protective clothing whilst applying the treatment. If you believe you or anyone in your family has also contracted ringworm, you should visit your doctor as soon as possible, and do not use the treatment prescribed for your cat.

Decontamination at home

It will be much easier to eradicate an outbreak of ringworm if it is feasible for you to restrain your cats in one room or area of the house, and one that is easily cleaned on a daily basis. Even heating and ventilation ducts should be vacuum cleaned, and all vacuum bags should be burned after use. All areas should be disinfected on confirmation of ringworm, and any bedding, toys or grooming tools that cannot be disinfected must be disposed of. Cardboard boxes and newspaper will make perfectly acceptable bedding in the short term.

Effect on breeding and showing

You should not take a cat to a show if it has any kind of skin lesion. If a cat is suspected of having ringworm at a cat show, it will be immediately rejected and the exhibitor and any other cats they may have at the show will have to leave the hall immediately. The Show manager is required to notify the Governing Council of the Cat Fancy, and the affected cat will need to be tested by the exhibitor's own Vet within 7 days, and the results notified to the GCCF. If the culture proves to be negative, the exhibitor will be given a clearance certificate to take to shows - although the cat still must not be shown until the skin problem has cleared up.GCCF encourages breeders and exhibitors to notify GCCF of an outbreak of ringworm, and breeding must cease. Owners of infected cats must not attend cat shows or meetings in any capacity until the problem has been confirmed as cleared, to minimise the risk of passing the infection onto other cats or people.


Any situations where there is interaction with other cats prevent a risk, including the introduction of new cats and kittens into your home. You should never share any bedding or grooming equipment with fellow exhibitors at a show, and if you are using a boarding cattery, you should check that your cats have exclusive use of such items. If you have any cause for concern, take your cats to the Vet to be tested straight away, and always keep areas used by cats regularly cleaned and disinfected.

How serious is ringworm?

It is generally not a life threatening condition, but it is highly contagious, which is why all steps should be taken to contain it. It is also not all that common, but is something that all cat owners and breeders need to be aware of, as it does appear from time to time.



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