Ringworm In Cats - General Overview Of The Disease
In spite of its name, ringworm isn’t actually a “worm”, but rather a type of fungus called dermatophytes.
Because of the characteristic circular lesions that they leave on the skin of infected animals and people,
the condition was given the name ringworm. Dermatophytes actually translate to “plants that live on
the skin”, which is appropriate given the fact that these fungi actually do live on the skin and in
the follicles, where they feed on dead tissue and hair. Although feline ringworm can be caused by three
different types of fungus, the most common cause is Microsporum canis.
Ringworm typically causes a round hairless lesion on the skin. In cats however, the characteristic "ring"
shape of the lesion doesn’t always occur, and you may instead see an irregularly shaped patch that can
grow to a fairly large size. What causes this characteristic look is the breaking off of the hair shafts
in the skin, resulting in areas with no hair. These patches usually occur on the face, the ears, the
tail and the paws. The lesions often take on a scaly appearance that may or may not be itchy. The skin
may also be slightly reddish and inflamed.
Cats usually pick up ringworm from another cat, a dog or even a human. Cats can also pass on the disease
to other animals and humans as well. It is important to keep in mind that the spores of the ringworm
fungus can stay alive without a host for a long time, and they can be found in carpets, blankets, brushes,
and combs, and can infect cats that come in contact with them. Ringworm can even be caused by contact
with soil wherein the fungus can live for several months.
Ringworm has an incubation period of 10 to 12 days, which means that it can take that long from initial
exposure to the appearance of lesions.
The good news is that otherwise healthy adult cats have usually built up enough immunity against the
ringworm fungus. Kittens typically don’t have such immunity however, since their immune systems aren’t
as fully developed. Furthermore, some animals can serve as carriers for the disease ands pass them on
to other animals, even though they themselves may show no signs of ringworm infestation.
Ringworm is typically diagnosed using any one of three tests: Wood’s Lamp, microscopic diagnosis, and
culture. These tests are necessary, since a feline ringworm diagnosis cannot be made just by looking
at the skin alone. The Wood's Lamp test involves using an ultra violet lamp, under which 50% of the
spores will glow. The microscopic diagnosis involves looking at some of the hair or skin from the lesions.
In the culture test, the vet will scrape the lesion and send it to a lab for analysis of the culture.