Cat Ringworm: Understanding a Zoonotic Disease

Cat ringworm, contrary to common belief, isactually not a type of worm but a fungus. This condition is onethat is often on your veterinarian’s list of possibilities when feline hairloss is present. This zoonotic disease can be transmitted from one animal toanother, including your cat to you and vice versa.

Unlike other types of hair loss in cats,ringworm often causes ring-shaped areas where your kitty’s skin is flaky, crusty,and red. It can be difficult to finally beat the symptoms of this zoonoticdisease, taking days to even weeks for the infection to clear up, but once ithas, anyone (cat or human) who has contracted this fungus will be immune tofuture infections if the individual has a healthy immune system. It's still a rather unpleasant, condition, though, so recognizing the signs and symptoms and starting prompt treatment will help you prevent the spread of this highly contagious fungal infection.

Symptoms of Cat Ringworm

Ringworm is a common problem with kittens orcats of any age, especially when they live in stressful environments, communalenvironments with other animals, or outdoors. Cats will often have severalareas on their bodies that are affected by this fungal infection, but areasusually look like circular sections of feline hair loss. Often, you’ll seeinflamed, red skin in the center and/or scabby, scaly, or flaky areas aroundthe edges.

Usually the hair loss in cats that is causedby ringworm will be found on the face or head area, around the ears or neck,paws (especially in the nail beds or folds of skin between toes), and/or tailbase. Sometimes, if the infection is bad enough, the areas can develop boilsthat ooze, but this is rare.

How is Cat Ringworm Transmitted?

Many cases of ringworm actually come from animalswho are carriers with no symptoms. Although cat ringworm is highly contagious,not every cat or human exposed to it will develop it. This is because of thecomplex immune response that develops upon exposure.

Feline ringworm may never infect a cat who has beenexposed, may cause an infection that shows no symptoms, or may cause obvioussymptoms like those described above. Other cats will simply become silentcarriers, or may continue to carry the fungus and transmit it to others evenafter he has fully recovered from his infection.

For a cat to develop ringworm, there has to be ascrape or scratch on the skin because the fungus is not able to penetrate andinfect your kitty otherwise. Contaminated grooming supplies, soil, or evenclothing or household objects can hold the fungus and infect you or your kitty.

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While history alone might point your vet in thedirection of cat ringworm as a diagnosis, there are very particular tests andequipment that can be used for a definitive answer. A Woods lamp is anultraviolet light source that causes the fungus to glow and can detect 50-75%of cat ringworm cases. Another test is a particular type of fungal culture,where your veterinarian will collect samples of hair from the edges of yourcat’s hair loss and some crusty skin samples to see if the fungus grows in aspecial disk.

In many cases, if you go to your vet with a kittenwith circular or oval patches of hair loss or bring a cat of any age who hascome from a shelter environment or recently been exposed to a shelter cat orkitten, your veterinarian will make the diagnosis just from the physicalsymptoms. Because the cat hair loss pattern is so atypical, in these cases, itcould be little else but cat ringworm.

Cat Ringworm Treatment

Cat ringworm,fortunately, will cure on its own even without treatment, but this can takequite a while to happen, so your veterinarian is likely to recommend treatingyour kitty. Doing so will help shorten the time it takes for the felineringworm to clear up and help reduce the threat of spreading the fungus to yourother pets or the humans living in your home. Successfully treating ringwormmeans treating your cat and the environment.

Because thespores can live in the environment, you’ll need to thoroughly vacuum, scrub,mop, and wash all surfaces with a solution of bleach and water at about a 1 to20 ratio. Steam cleaning area rugs, upholstered furniture, and othernon-washable fabrics is also recommended, and your cat’s bedding should bereplaced or washed thoroughly.

To reduce thespread of spores, you should wear gloves and change clothing after handling acat with ringworm. It is often recommended that you separate cats with symptomsfrom those who do not appear to have symptoms, although it’s also commonpractice to treat the entire household of cats, since most have beenexposed and treatment, depending on the option chosen, can be very safe.

Lime sulfur dipsare, by far, the most safe and effective treatment of  ringworm in cats. Many oralmedications can have very serious side effects, and cats often have toxicreactions to other types of topical and oral treatment. For this reason,although it does involve more work, lime sulfur treatments are the best optionfor cat ringworm treatment.

The only disadvantage to lime sulfur dips is that theprotocol will require several weeks of treatment (essentially bathing yourcat). This can be difficult for some cat owners, but your veterinarian willoften be able to do so at his/her office for you. These dips smell awful andmay cause your kitty’s skin or hair to turn yellow temporarily, but you’ll beglad you chose this safe and effective way of clearing up your kitty’sinfection! Ask your vet about the best way to conduct lime sulfur treatments.

Prevention and More Information

Ringworm is ahighly contagious fungus, but fortunately, it is not life-threatening and evenwithout treatment will often self-cure. You can prevent the spread of ringworm by getting a diagnosis and beginning treatment as soon as possible,along with sanitizing as much of your home as possible.

For furtherinformation about ringworm and other information about hair loss in cats,please see the following articles:

Cornell Feline Health Center (opens in new window)

Learn more about Zoonotic Diseases

More information about Hair Loss in Cats

Cat Flea Allergies

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