How Do Cats Get Ringworm?

A common plight of rescued kittens, ringworm is a highly contagious condition that spreads quickly in shelters and multi-cat homes. Yet, even indoor-only cats from single-cat homes are occasionally affected.

While ringworm is usually not serious or life-threatening, it can take weeks of aggressive treatment to rid your cat of the ring-shaped rash. Learn how cats contract ringworm and what to do if your cat may have picked up this stubborn skin condition.
 

What Is Ringworm in Cats?

Despite its name, ringworm is not caused by a parasite. It’s caused by a type of fungus called a dermatophyte, which feeds on keratin, a protein that makes up skin, hair, and nails. Almost all cases in cats are caused by the microsporum canis strain, though other strains of fungus can also cause ringworm.
 

How Does Ringworm Spread?

Ringworm is highly contagious, spreading by producing spores in the outer layer of the skin, hair, or nails.

People and other animals can contract ringworm by coming in direct contact, for example, by brushing, petting, holding, or cuddling the affected animal.

Broken hairs and dead skin particles that the affected animal sheds can spread spores throughout their environment. These spores can survive on surfaces for up to 18 months.

Making contact with ringworm spores does not guarantee that a person or pet will be infected. Minor skin trauma like brushing, shaving, and scratching enables the spores to penetrate the skin and cause an infection.
 

How Did My Cat Get Ringworm?

Kittens, senior cats, and cats with a compromised immune system due to illness or stress are more likely to contract ringworm.

It’s common for cats to contract ringworm after direct contact with an infected cat while roaming outdoors or in an animal shelter. Cats greet one another by rubbing their heads together - which explains why it’s so common for the rash to show up on and around their face.

Cats can also contract ringworm at the groomer’s, especially if brushes, clippers, or other equipment is not thoroughly sanitized between clients. Symptoms of ringworm in cats usually show up after an incubation period of around 10 to 14 days.

Ringworm is contagious during the incubation period, before any rash is apparent. It is also possible for cats to carry infectious spores on their coat without being infected themselves.
 

Should I Take My Cat To The Vet For Ringworm?

Yes, you should see your veterinarian as soon as possible if your cat has ringworm.

Even though the condition is self-limiting, typically clearing up on its own, it can take months for the immune system to clear the infection without treatment. Untreated ringworm is contagious until the rash has healed and can leave your cat susceptible to secondary skin infections.

Your veterinarian will examine your cat to determine if it’s likely they have ringworm or if it may be another skin condition. They may use a specialized UV light called a Wood’s Light, under which the affected skin will glow bright green if your cat has ringworm, though this test is not always 100% reliable.

The most accurate way to diagnose ringworm in cats is with a fungal culture, though it takes up to three weeks to complete. In the meantime, if your veterinarian determines that ringworm is likely, they will recommend starting treatment right away.
 

Should I Avoid Petting My Cat If They Have Ringworm?

Yes, you should limit petting and handling your cat while they have ringworm. In kittens and newly adopted cats, though, socialization is essential, and can be done with precaution.

While ringworm is highly contagious, it’s not guaranteed that you will be infected if you pet your cat. Spores cannot infect healthy, unbroken skin. However, mild skin trauma, like brushing, scratching, shaving, or friction from clothing is enough to allow spores to cause an infection. Also note that it takes about six hours for spores to begin to germinate on your skin.

So, if you do pet your cat, avoid touching their lesions. Wash your hands immediately after contact, not only after petting your cat, but also after handling contaminated items like bedding and toys. Make sure to shower and launder clothing with extended contact, for example, if your cat sits in your lap or rubs up against your legs.
 

How Is Ringworm in Cats Treated?

Ringworm in cats is treated through the use of topical antifungal medications, oral antifungal medication, and by sanitizing the cat’s belongings and environment.

You may decide to keep your cat in an easily cleanable area, like a bathroom or laundry room, to prevent spores from shed hairs and skin from spreading throughout your home. Diluted bleach or surface disinfectant is best for cleaning hard surfaces, while laundering bedding and other soft items in hot water will kill the spores.

Apply an antifungal ointment like clotrimazole cream several times each day as instructed on the packaging or as instructed by your veterinarian. Bathe your cat with medicated antifungal shampoo several times a week or as instructed. Use gloves when applying topical treatment.

Your veterinarian may also prescribe an oral antifungal medication, which should be administered in conjunction with topical treatment and environmental disinfection.

Ringworm in cats is contagious for about three weeks after starting treatment. During that time, it will be necessary to isolate your cat from people and other pets. See your veterinarian if symptoms worsen or persist, and contact your primary care physician if you or a family member contract ringworm from your cat.