Dermatophytosis’ or Ringworm is the most common fungal skin infection in cats and it is caused by fungus which invades the outer dead layers of the skin, claws and hair. It is most common in areas of high humidity and temperatures, and usually causes a circular like lesion on the cat’s skin.
Ringworm is common throughout the world and most often presents in young cats who live in crowded surroundings such as animal shelters or catteries.
Ringworm is extremely contagious. A cat can become infected with ringworm either by direct contact with an infected animal or via the environment, such as contaminated bedding, grooming equipment, carpet, furniture and soil. The spores are attached to the hairs, which are shed into the environment and can remain infective for up to 18 months.
The Symptoms typically appear two weeks after exposure.
- The most recognisable sign that a cat is infected with ringworm is the presence circular patches of rough, scaly skin with a red outline and broken hairs or bald patches. It is found most often on the head followed by the limbs and tail, however any part of the body can be affected. Lesions may range from small and barely noticeable to severe, affecting large parts of the body. These lesions do not appear to be itchy in most cats.
- Infection of the claws may present as claws which are easily broken, flaky, crusted and malformed.
- Severe cases of ringworm may lead to infection or inflammation of the hair follicles and/or secondary infection of the skin.
Up to 20% of cats are asymptomatic carriers. This means that they carry the fungus but show no signs of infection.
Once a cat has been diagnosed with ringworm, it is imperative to treat both the cat and its environment. If it lives in a multiple cat situation, all the cats will need to be treated. It is important that all cats are confined to just one area whilst they are being treated to avoid spreading spores around the home.
Treatment involves frequent saturation and washing of the cat with a prescribed antifungal solution over a number of weeks. Your vet will be able to recommend the most appropriate product and will also be able to check the progress of the treatment via a Wood’s lamp test.
Gloves must be worn when handling a cat with ringworm and clothes changed immediately afterwards. They should be washed in an anti-fungal rinse to kill any spores that may have been picked up.
Carpets and soft furnishings should be vacuumed daily and the vacuum cleaner bag disposed of. Steam cleaning is also highly recommended. Bedding and kennels will need to be disinfected and this repeated weekly. Diluted bleach (one-part bleach to ten parts water) may be used to clean down surfaces and floors and any other equipment used on the cat such as grooming combs etc.
In healthy cats, ringworm will often resolve itself in two to four months. However, it is recommended that you treat the cat for ringworm to speed up the process and prevent infection of humans and other pets.
Sometimes long haired cats will need to be shaved during treatment as the fungus can become trapped in long coats, making it harder to treat. Short haired cats don’t need to be shaved unless the infection covers a large area of their body.
It is possible for humans to catch ringworm from cats and vice versa. Children (especially under 10 years old) or adults who are in poor health, undergoing chemotherapy or have a weakened immune system, such as those with HIV, are more likely to become infected than healthy adults. Keep affected cats/children apart to avoid spreading the fungus.
How is ringworm in humans treated?
If you (or anybody in your household has ringworm), treatment with a suitable antifungal ointment or cream is necessary. This is usually applied 2-3 times a day to the affected area(s) for several weeks. Cover ringworm lesions with a plaster/band aid to avoid spreading the infection to other people and pets.
Bedding and towels should be washed regularly (using an antifungal rinse) and towels and other personal items should not be shared with a person infected with ringworm.