How Long Should You Quarantine a Cat With Ringworm? (Vet Answer)

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Written by

Dr. Leigh Wilder

Veterinarian, DVM

The information is current and up-to-date in accordance with the latest veterinarian research.

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What Is Ringworm?
What Does Ringworm Look Like?
How is Ringworm Spread?
Next Steps
Treatment
Quarantine Guidelines
Prognosis

Crusty skin, hair loss, and itching are signs no cat owner wants to see in their pet. But what do these signs mean? Could your cat have ringworm, and if so, what do you need to do? The following guide will discuss this contagious condition in cats and detail guidelines for quarantining your cat while they undergo treatment recommended by your veterinarian. Cats are typically contagious for around three weeks after initiating therapy,

What Is Ringworm?

Ringworm, also known as dermatophytosis, is a common fungal infection of the hair, skin, and nails. Despite its name, ringworm is not caused by worms but by dermatophytes—microscopic organisms that come from the soil and infect various host species. Microsporum canis is the dermatophyte most commonly responsible for ringworm in cats; this specific dermatophyte may also infect dogs and humans.

Close-up ringworm on cat's leg — Image Credit: Nadya Bessonov, Shutterstock

What Does Ringworm Look Like?

Signs of ringworm in cats may vary, however, commonly include:

Circular areas of hair loss
Stubbly or broken patches of hair
Crusty or scaly areas of skin

Less common signs of ringworm may also be noted, and can make obtaining a diagnosis more challenging:

Abnormal nails or nail beds
Bumps or nodules on the skin
Increased skin pigmentation
Pruritis (itching)

Ringworm can be noted anywhere on the body; however, the face, ears, feet, and tail are most frequently affected.

How Is Ringworm Spread?

Ringworm is a contagious, zoonotic disease– meaning it can spread from animals to humans. Transmission is common from direct exposure to infected cats; however, spread can also occur from contact with contaminated objects such as grooming tools, toys, bedding, or clothing. Ringworm can persist in the environment for years, causing additional infections unless contaminated areas are properly cleaned.

Ringworm zoonosis — Image Credit: Ternavskaia Olga Alibec, Shutterstock

Next Steps if Ringworm Is Suspected

If you think your cat may have ringworm, a visit to the veterinarian is needed for further evaluation. Your veterinarian may diagnose ringworm based on a combination of physical exam findings and diagnostic tests, including Wood’s lamp evaluation, direct microscopic examination, fungal culture, and fungal PCR.

Ringworm Treatment

Once ringworm has been diagnosed in your cat, your veterinarian will discuss treatment options. Treatment typically involves systemic therapy with oral medication, topical therapy, and environmental decontamination:

Systemic therapy – Oral medication is an essential component of ringworm treatment as it stops the active infection and proliferation of the fungus. Itraconazole and Terbinafine are two commonly used oral medications your veterinarian may recommend.
Topical therapy – Topical anti-fungal products aim to reduce the risk of ringworm transmission by disinfecting an affected animal’s hair coat. Along with oral medication, your veterinarian may recommend twice-weekly lime sulfur rinses and certain medicated shampoos as safe and effective treatments for ringworm.
Environmental decontamination – Removing fungal spores from the environment is an important component of ringworm treatment and will help minimize the treatment duration needed for an infected cat. Disinfection of contaminated areas in the home should be considered as follows:

For nonporous surfaces – Vacuuming or sweeping is needed to remove debris. This should be followed by washing the affected surface with a detergent and rinsing clean. Lastly, a disinfectant (such as bleach) may be applied to kill any remaining fungal spores.
For laundry – Contaminated clothes or bedding can be effectively cleaned twice during the longest wash cycle.
For carpets – Initial vacuuming, followed by washing twice with a carpet shampooer and detergent, was effective in decontamination.
For wood floors – Daily removal of debris with dry, disposable cleaning clothes, along with twice-weekly washing with a wood oil soap, is recommended.

See Also: 8 Home Remedies for Treating Ringworm in Cats

Cat checked by Vet — Image Credit: Stock Asso, Shutterstock

Ringworm Quarantine Guidelines

After obtaining a ringworm diagnosis and starting treatment, your veterinarian will likely discuss quarantine recommendations for your cat. A quarantine, or period of isolation, is recommended for cats with ringworm to minimize the potential spread of the disease to other animals or humans. When a small area of the house is chosen for quarantine (such as a bathroom), it also allows for easier and more effective environmental decontamination. Key points that should be considered regarding quarantining your cat for ringworm include:

Duration – Your veterinarian will discuss how long they recommend quarantining your cat during ringworm treatment. Infected felines are typically contagious for around three weeks after initiating therapy. However, multiple factors (such as your cat’s age or immune system status) may affect quarantine duration. Fungal cultures will be used by your veterinarian to more accurately determine when your cat is no longer contagious.
Frequency of cleaning – Hair and other obvious debris from where your cat is quarantined should be cleaned daily. Twice weekly disinfection of this area is also recommended.
Precautions – Due to the contagious and zoonotic nature of ringworm, basic precautions should be taken while you are caring for your cat. While cleaning or interacting with your cat, wearing gloves and a long-sleeved shirt and pants is recommended to minimize the risk of ringworm transmission. Thoroughly washing hands after any interaction is also important. Children and immunocompromised individuals should avoid contact with infected cats, as they may be at a higher risk of contracting ringworm.

Ringworm Prognosis

In our feline friends, ringworm can be a frustrating and labor-intensive disease to manage. Thankfully, ringworm is a very treatable condition with a good long-term prognosis. Treatment duration may vary, and response to treatment is often monitored with repeated fungal cultures. A cat is typically considered cured once two negative ringworm cultures have been obtained, 2-4 weeks apart. It is important to note that treatment for ringworm should not be discontinued until recommended by your veterinarian.

Conclusion

With a collaborative approach to treatment and a clear discussion of quarantine recommendations, veterinarians and cat owners can work together to make ringworm treatment as smooth and stress-free as possible!

Featured Image Credit: EVGEIIA, Shutterstock