What is Ringworm?
Ringworm is not actually caused by a worm, but is a highly contagious fungal infection of the skin, hair, and nails. It is caused by dermatophyte fungi such as Microsporum canis and Trichophyton mentagrophytes. Despite its name, ringworm does not have anything to do with worms. The name comes from the ring-shaped rash that is a common symptom.
Ringworm fungi thrive on keratin, the key protein found in skin, nails, and hair. The fungi burrow into the outer layer of the skin and cause lesions as the infection spreads outward. As the lesions enlarge, the center often heals, creating the classic ring-shaped rash.
While ringworm goes by only one name, there are different types of ringworm infection depending on the area of the body affected:
- Tinea capitis – scalp ringworm
- Tinea corporis – body ringworm
- Tinea cruris – groin ringworm or “jock itch”
- Tinea manuum – ringworm on the hands
- Tinea pedis – athlete’s foot or ringworm on the feet
- Tinea unguium – ringworm affecting the fingernails or toenails
Symptoms of Ringworm
The most common symptom of ringworm in dogs is a circular, red, raised rash. This rash often results in hair loss in patches, giving it a ring-like appearance. The edges of the rash may appear scaly and inflamed. As the infection spreads outwards, the center of the ring often heals, resulting in the classic “ring” shape.
Other symptoms include:
- Hair loss, usually in circular patches
- Red, inflamed skin
- Crusting or scaly skin
- Brittle, discolored nails
The rash can appear anywhere on the body. Areas like the head, legs and around the muzzle are commonly affected. Ringworm usually starts as a small lesion that expands over time if left untreated (Source: https://www.akc.org/expert-advice/health/ringworm-in-dogs/).
In some cases, the rash and hair loss may be mild or even go unnoticed. Ringworm often goes undiagnosed in dogs that have thick coats. Owners may mistake early cases as simply dry, flaky skin. However, ringworm tends to worsen and spread if not treated.
Over-the-Counter Treatments
There are several over-the-counter antifungal medications that can be used to treat ringworm in dogs. Some common active ingredients in OTC ringworm treatments include:
- Miconazole – This is found in antifungal creams like Monistat and Fungicure.
- Clotrimazole – This is the active ingredient in antifungal creams like Lotrimin and Desenex.
- Ketoconazole – This is found in antifungal shampoos like Nizoral.
These OTC topical antifungals work by preventing the growth and spread of fungal infections on the skin. They are available as creams, ointments, lotions, shampoos, and sprays. Some popular over-the-counter brands for treating ringworm in dogs include Lotrimin, Miconazole, and ketoconazole shampoos.
When using OTC antifungals, it’s important to follow the label instructions closely and treat the entire area thoroughly. Treatment may need to continue for several weeks until the infection clears up completely.
Effectiveness of OTC Treatments
Over-the-counter antifungal products can be effective for treating mild cases of ringworm in dogs, but they typically take consistent use over several weeks to fully clear the infection.
Some common OTC topical treatments for ringworm in dogs include miconazole, clotrimazole, and terbinafine creams or ointments. According to WebMD, these topical antifungals help stop the spread of infection and provide symptom relief when applied daily to affected areas for 2-8 weeks (1).
OTC antifungal shampoos containing ingredients like miconazole, chlorhexidine, or ketoconazole can also help treat ringworm. Bathing your dog 2-3 times per week with a medicated shampoo may speed up recovery (1).
While OTC treatments can be effective, they must be used consistently for several weeks to fully clear a ringworm infection. GoodRx notes that skipping applications or stopping treatment too soon increases the risk of recurrence (2).
If your dog’s ringworm does not start to improve within 2-4 weeks of consistent OTC treatment, veterinary care is recommended, as prescription oral or topical antifungals may be needed for more stubborn infections (1).
(1) https://www.webmd.com/pets/dogs/dog-ringworm-remedies
(2) https://www.goodrx.com/pet-health/dog/ringworm-in-dogs
When to See a Vet
While mild cases of ringworm often clear up with over-the-counter treatment, it’s important to seek veterinary care if the infection spreads or persists beyond 4 weeks of at-home treatment. According to the BlueCross, if the ringworm is getting worse or your dog seems unwell, take them to see the vet straight away.
Specifically, the BlueCross recommends seeing a vet if:
- The ringworm is spreading to other areas of your dog’s body or to other pets.
- Your dog is scratching excessively or seems in discomfort.
- Hair loss/bald patches are increasing.
- Scabs or sores develop.
- Your dog seems lethargic or unwell.
- OTC treatments haven’t cleared up the infection after 4 weeks of use.
The vet can prescribe oral antifungal medication, medicated shampoos, or topical creams that may be more effective for stubborn ringworm infections. They can also rule out other skin issues that may require different treatment. Catching ringworm early and treating aggressively improves the prognosis.
Sources:
https://www.bluecross.org.uk/advice/dog/health-and-injuries/ringworm-in-dogs
Prescription Medications
Veterinarians may prescribe oral antifungal medications to treat ringworm in dogs. Some common prescription antifungal pills given for ringworm include:
- Griseofulvin (Fulvicin, Gris-Peg, Grisovin) – one of the oldest and most commonly prescribed oral antifungals for dogs with ringworm, according to https://vcahospitals.com/know-your-pet/ringworm-in-dogs
- Itraconazole (Sporanox, Itrafungol) – a newer, broad-spectrum antifungal medication used for ringworm in dogs, according to https://vcahospitals.com/know-your-pet/ringworm-in-dogs
- Terbinafine (Lamisil) – effective against dermatophyte fungi that cause ringworm, often prescribed with topical creams, according to https://www.goodrx.com/pet-health/dog/ringworm-in-dogs
These oral antifungal medications help treat the ringworm infection systemically from the inside out. The length of treatment is typically 4-8 weeks. Veterinarians may also prescribe antibiotics if a secondary bacterial skin infection develops along with the ringworm fungal infection.
Home Remedies
There are some natural home remedies that can help treat ringworm in dogs when used in conjunction with over-the-counter antifungal treatments. Some popular home remedies include:
Apple Cider Vinegar
Apple cider vinegar contains acetic acid which has antifungal properties. Diluting apple cider vinegar with water and applying it to affected areas can help kill ringworm fungi. Be sure to rinse thoroughly after 15-30 minutes to avoid irritation. According to https://www.dogsnaturallymagazine.com/naturally-control-dogs-ringworm/, apple cider vinegar is a gentle yet effective home remedy for ringworm in dogs.
Tea Tree Oil
Tea tree oil is a natural antifungal that can help treat ringworm when applied topically. Always dilute tea tree oil before applying it to the skin as it can cause irritation when used undiluted. According to https://wagwalking.com/treatment/natural-ringworm-remedies, tea tree oil is one of the most popular natural remedies for ringworm in dogs.
Garlic
Garlic contains antifungal compounds that may help inhibit the growth of ringworm. Feeding dogs garlic supplementation or rubbing diluted garlic oil on affected areas could aid in ringworm treatment. Consult your vet before giving your dog garlic, as the appropriate dosage depends on your dog’s size. As noted by https://www.dogsnaturallymagazine.com/naturally-control-dogs-ringworm/, garlic can be an effective natural treatment for ringworm in dogs.
Prevention
There are a few key things you can do to help prevent ringworm in your dog:
Practice good hygiene and bath your dog regularly using an antifungal shampoo like miconazole or chlorhexidine. Make sure to thoroughly clean and disinfect any areas of your home where your dog sleeps or spends time.
Don’t share any grooming supplies like brushes, towels or clippers between dogs, as this can spread the fungus. Always sterilize grooming tools after each use. And be sure to wash your own hands after handling an infected dog.
Avoid areas where the fungus is likely present, like places with a lot of stray or neglected animals. Keep your dog away from burrows, as rodents can carry ringworm.
Boost your dog’s immune system with good nutrition and appropriate vaccines. A strong immune system will be better able to fight off infection.
Promptly treat any skin issues your dog develops, as damaged or inflamed skin is more prone to ringworm infection. Keep your vet informed if ringworm is identified so they can help prevent its spread.
Cleaning and Disinfection
To prevent the spread of ringworm, it’s important to thoroughly clean and disinfect your home.
Frequently vacuuming carpets, furniture, and pet bedding can help remove skin scales and fallen hairs that contain ringworm spores. Use a vacuum with a HEPA filter for best results (1).
Disinfect all hard, non-porous surfaces in living areas using a diluted bleach solution (1 part bleach to 10 parts water) or an over-the-counter disinfectant labeled to kill fungi and ringworm. Focus on areas your pet frequents like floors, furniture, countertops, pet crates, food and water bowls, and toys (2). Allow surfaces to air dry after disinfecting.
Wash pet bedding, blankets, curtains, and other fabrics regularly in hot water and dry thoroughly. Items that can’t be washed can be disinfected with a spray containing chlorine bleach or another EPA-registered fungicidal agent and allowed to air dry (3).
Thoroughly cleaning and disinfecting your home while treating your pet for ringworm can help stop the fungus from spreading and reinfecting your dog.
Prognosis
The prognosis for dogs with ringworm is generally good with prompt treatment. According to the AKC, ringworm usually clears within 2-4 weeks when treated properly with medications prescribed by a veterinarian.1 The key is starting treatment as soon as ringworm is diagnosed to prevent the fungal infection from spreading to other areas of the dog’s body or to other pets and people in the household.
Some important points about the prognosis of ringworm in dogs:
- With oral and topical antifungal medications, most dogs make a full recovery within 1-2 months.
- Dogs should be rechecked by a vet in 2-4 weeks to confirm the infection is resolving.
- Treatment must be continued for 2-4 weeks until skin cultures are clear to prevent recurrence.
- Prompt diagnosis and treatment prevents ringworm from spreading to other pets or humans.
- Without treatment, ringworm can spread and become a stubborn infection taking months to clear.
In summary, the prognosis for ringworm in dogs is good when appropriate treatment is started right away under a veterinarian’s supervision. Consistent, thorough treatment for an adequate length of time is key to preventing recurrence and spread of this contagious fungal infection.