Ringworm in Dogs

Feb 24, 2025 Leave a comment

Ringworm is one of the most common fungal skin infections in dogs. It’s a fungal infection affecting skin, hair, and nails. It’s highly contagious and can easily spread between animals and humans. It can cause discomfort for your pet, but with early intervention and proper care, you can help your dog recover quickly, and prevent future infections.

What is ringworm?

Despite the name ringworm, it isn’t actually caused by a worm. It’s a skin infection from a type of fungus called dermatophytes. It thrives in warm, humid environments and feeds on keratin, the protein found in skin, hair, and nails. The infection typically appears as red, scaly skin lesions in the shape of a ring, where the term "ringworm" comes from.

How does ringworm spread?

Ringworm is highly contagious in dogs and spreads through direct or indirect contact with infected animals, humans, or contaminated objects. The fungus can survive on surfaces like bedding, grooming tools, and furniture for months, making thorough cleaning critical to prevent reinfection.

Common ways ringworm cases spread:

Direct contact: touching an infected pet or person.
Contaminated objects: grooming tools, furniture, and toys.
Outdoor exposure: dogs that love spending time digging or rolling in dirt can be infected by ringworm spores in the soil.

Recognizing the signs and symptoms

Pet owners must learn to spot the signs of ringworm, as catching it early is crucial for preventing the infection from spreading. Although the symptoms may vary, there are physical and behavioral changes to watch for in your dog.

Visible symptoms

Circular areas of hair loss: These spots may be red, scaly, or crusty and are normally on the head, ears, paws, or tail.
Brittle or misshapen nails - if the claws are affected.
Musty odor from the infected areas.

Behavioral changes

Dogs with ringworm are often itchy and uncomfortable, which can lead to behavioral changes. These symptoms can mimic other conditions, such as allergies or bacterial infections, so a veterinary diagnosis is essential.

Excessive licking, chewing, or scratching at affected areas.
Rubbing against furniture or rolling on the floor for relief.
Restlessness or irritability due to constant skin irritation.

Diagnosing ringworm in dogs

Because the symptoms of ringworm in dogs can look like other skin conditions, your veterinarian will need to run tests to confirm the diagnosis. Early diagnosis and treatment stop the infection from spreading further, and make sure your dog gets the care they need. Common diagnostic methods:

Wood’s lamp examination uses an ultraviolet lamp to detect spores. Some strains glow green under the light, but not all strains glow, so additional testing is often needed.
Microscope examination of skin cells or a hair sample to look for fungal spores.
A fungal culture is the gold standard for diagnosing ringworm in dogs. A hair or skin sample is placed on a culture to encourage fungal growth, which can take up to 14 days to confirm.
PCR testing analyzes skin or hair samples in a lab. It’s useful when other methods are inconclusive or will take too long – results are usually back within 1-3 days. It’s a sensitive test, so is helpful for earlier detection and also identifying the specific species of fungus.

Treating ringworm: What works best?

A combination of oral and topical medication will typically be prescribed. The approach your vet recommends will depend on the severity of the infection.

Veterinarian treatment options

Topical treatment: Medicated shampoos, creams, or ointments applied directly to the affected area.
Oral medications are necessary for severe or widespread infections. These medications work from the inside out to eliminate the fungus.

Proper treatment resolves most cases in 4 to 6 weeks, but chronic or serious cases may take longer. Part of treatment is a thorough cleaning of your home to prevent the infection from spreading or returning.

Safe and effective home remedies

Professional care is important for treating cases of ringworm in dogs, but there are home remedies that can help support the healing process. Always consult your vet before trying these remedies to be sure they don’t interfere with prescribed treatments.

Medicated shampoos: To reduce fungal growth, bathe your dog with antifungal shampoo twice a week. Leave the shampoo on for 10 minutes before rinsing.
Apple cider vinegar: Mix apple cider vinegar with water (1:1 ratio) and apply it to the affected area to help restore your dog’s skin’s natural pH balance.
Coconut oil: Apply directly to soothe irritated skin and help kill the fungus with its antifungal properties. This may only work in very mild cases.
Environmental cleaning: This step is essential to prevent reinfection. Clean your dog’s living space, bedding, food bowls, and grooming tools thoroughly, along with the areas in the house where the dog spends a lot of time.

Remember, home remedies should support — not replace — professional treatment.

Preventing ringworms in dogs

Because this is a fungal infection, preventing future outbreaks requires a combination of good hygiene, a strong immune system, and environmental management.

Hygiene and environmental cleaning

Clean kennels, bedding, and toys frequently using hot water with bleach or an antifungal disinfectant.
Vacuum frequently to remove fungal spores from carpets and furniture.
Disinfect grooming tools and avoid sharing them between pets.
Isolate infected pets until they’ve fully recovered, to prevent spreading the infection.

Boost their immunity

A strong immune system helps dogs resist infections, and dogs with weaker immune systems are more prone to these infections. A healthy diet plays a vital role in preventing fungal infections. Nutrient-dense food helps strengthen the skin’s natural barrier and boosts the immune system. Support your dog’s overall health with:

Probiotics to promote gut health and skin resilience.
High-quality protein sources to maintain healthy skin and coat.
Omega-3 fatty acids (found in fish oil) to reduce inflammation.
Probiotic-rich foods like yogurt or kefir to support gut health.

Ringworm can be a frustrating condition, but with early detection, proper treatment, and thorough cleaning, your dog can make a full recovery and prevent future infections. By understanding how it spreads, recognizing the symptoms, and taking proactive measures to keep your home clean, you’ll safeguard your pet and family from this common fungal infection.

Frequently Asked Questions

Ringworm in specific dog breeds: Who’s at risk?

While any dog can get this infection, some breeds are more prone due to their coat type or skin structure.

Breeds with thick coats (Golden Retrievers, German Shepherds) are at higher risk because the dog’s fur is dense, and trapped moisture creates an ideal environment for fungi.
Breeds with skin folds (Bulldogs, Shar Peis) are also more susceptible because fungi thrive in warm, damp areas.

Regular grooming and early intervention are crucial if you own a breed prone to skin issues.

Can humans catch ringworm from dogs?

Yes. Ringworm is zoonotic, meaning it can spread between animals and humans. Always wash your hands after handling an infected dog and avoid direct contact with infected areas. Read more about how it typically presents in humans .