Ringworm Treatment for Cats & Dogs

Ringworm is a contagious fungal infection that can affect humans as well as domestic animals like cats and dogs. The name is somewhat misleading - this condition is not caused by a worm. Ringworm infections get their name from the round, red, raised, ring-shaped areas of inflammation that develop on the skin, hair shafts, and nails of an infected animal. Please continue reading to learn more about treatment options for ringworm in dogs and cats.

What causes ringworm in pets?

The fungi that cause ringworm are called dermatophytes, for example, Microsporum canis and Microsporum gypseum. Some dermatophytes are specific to a species, i.e., they affect only cats. Others can spread from humans to animals and vice versa and between different species of animals. For example, one species of dermatophytes is responsible for all ringworm infections in cats. This ringworm fungus can also spread to dogs and humans.

How does a ringworm infection spread?

Ringworm spreads through direct contact with an infected skin lesion (fungal spores are present in the skin lesions of an infected animal). Transmission also occurs through contact with a pet’s contaminated environment, including objects belonging to an infected pet (grooming tools, food, and water bowls) and surfaces such as bedding and furniture. It’s important to wear gloves when handling infected animals and to wash your hands carefully afterward.

Not all exposures to fungal spores result in a ringworm infection. The risk depends on various factors, such as your pet’s age and overall health status. For example, if your pet has a compromised immune system or is a puppy or senior dog, the risk of catching ringworm is higher. The fungus is less likely to infect healthy adult animals with intact skin.

Keep in mind that fungal spores are microscopic spores that are not easy to identify with the naked eye. Moreover, these fungal spores can survive in the environment and remain dormant but contagious for up to 18 months. For effective treatment, you need to carefully clean and disinfect your home after treating ringworm in infected cats and dogs to prevent reinfection.

What do ringworm lesions look like?

Ringworm lesions are round, red, raised, ring-like areas of scabby, inflamed skin. However, there may not be obvious skin lesions, and when present, they may not always be ring-shaped. There can be a cigarette-ash-like scaling present under the coat on the dog’s or cat’s skin. There can also be circular, thickened patches of hair loss in areas with infected hairs. Severe ringworm infections can cause more widespread hair loss due to weakening of the hair shaft. If the claws are involved, clinical signs may include rough, pitted, brittle, scaly, or deformed claws.

How do veterinarians diagnose ringworm fungi?

Veterinarians can diagnose cats’ or dogs’ ringworm infections with a special ultraviolet lamp (Wood’s lamp) where the ringworm spores show up as yellow-green fluorescent. However, to confirm ringworm, they need to send ringworm cultures to the lab. The vet will take a sample of scrapings from a suspected ringworm lesion on your pet’s skin and send it to the laboratory for a fungal culture. The results may come back in a couple of days but can sometimes take up to 3 weeks because the fungal spores are slow to grow.

How do you get rid of ringworms in cats and dogs?

The appropriate treatment for ringworm fungal infections in cats and dogs consists of a combination of topical therapy in the infected areas and oral antifungal medications. Sometimes, an oral anti-fungal drug is not necessary, and topical treatment alone is prescribed.

Pets with compromised immune systems are at a higher risk to catch ringworm and develop severe infection. Therefore, they may require more aggressive treatment.

If there is more than one pet in your household, your veterinarian will ask you to separate the infected animals from other animals who are not infected. Sometimes, the vet may recommend ringworm treatment for all your pets at the same time. In addition, the infected pets’ environment needs to be disinfected to prevent reinfection.

What is the medicine to treat ringworm in cats and dogs?

Topical Therapy

Creams and ointments, such as terbinafine (Lamisil), miconazole (Micaved), and clotrimazole (Otibiotic, Otomax), can be applied to the affected areas for directly killing fungal spores. Your veterinarian may also recommend using a lime sulfur or chlorhexidine and miconazole shampoo twice a week. Topical therapy for a ringworm infection needs to continue for up to four weeks or longer. Stopping treatment too soon can cause the infection to come back.

If only one or two small areas are affected, you could shave the hair in those affected areas. However, if the infected cat or dog has a more generalized ringworm infection or if your pet is a long-haired breed, you may need to clip all the pet hair.

Use only products recommended by your veterinarian for topical treatment of ringworm in cats and dogs. After treating your pet, wash your hands and disinfect all surfaces and objects with a dilute bleach solution.

Oral Medications

Almost all ringworm infections in cats and dogs require oral medication. The veterinarian may prescribe an oral anti-fungal drug such as terbinafine or itraconazole (Sporanox, Itrafungol, Onmel). The treatment usually takes 6 weeks, longer if the infection persists.

What is the fastest way to treat a ringworm infection in cats?

The fastest way to treat feline ringworm or canine ringworm is to follow your veterinary medicine expert’s advice and give your pet the topical treatment and oral medications prescribed. Also, be sure to reduce environmental contamination to prevent ringworm from spreading to other pets in the household or coming back after successful treatment.

During ringworm treatment, you may find it convenient to keep your pets in rooms with hard floors that are easier to clean and disinfect. If this is not possible, daily vacuuming of carpets, furniture, and other surfaces can help prevent the spread of the ringworm infection.

Can I treat my cat’s ringworm fungal infection myself?

The medications that are used to treat ringworm in dogs and cats are prescription drugs. You cannot buy them over the counter without an order from your veterinarian. Moreover, the ringworm medications meant for humans may not be suitable for your pet. There are no proven home remedies for ringworm in cats and dogs. Therefore, home treatment of your cat’s or dog’s ringworm is not advisable.

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