Ringworm, that deceptive misnomer! Contrary to its name, this irritating intruder isn't a worm but a fungus, specifically a dermatophyte. Dermatophytes, the culprits behind ringworm, feast on dead skin and hair cells, creating a variety of skin lesions in animals. Unlike the classic round, red ring seen in humans, animals display diverse skin manifestations, making diagnosis a challenge.
How Infections Occur
Dermatophyte spores, resilient in the environment, can last for years. Infection occurs when these spores come into contact with abraded skin – freshly shaved, scraped, or scratched areas are especially vulnerable. Transmission can happen through contact with an infected symptomatic animal, asymptomatic carrier, or contaminated environment. Notably, different species of dermatophytes originate from different sources, aiding in identifying the infection's origin.
Is Ringworm Contagious to Humans?
Yes, ringworm can be contagious to people, particularly those with compromised immune systems. Young animals, children, pregnant women, elderly individuals, and pets, along with those undergoing chemotherapy or organ transplant medication, are at higher risk. Skin irritation is necessary for infection.
Diagnosing Ringworm
Diagnosing ringworm in animals is often tricky due to atypical lesions. Various methods aid in confirmation:
- Wood's Light (Fluorescence): Microsporum fungi fluoresce apple green under Wood's light. However, false negatives and fluorescing debris complicate diagnosis.
- Microscopic Examination: Hairs are examined for spores, although they can be challenging to spot, especially in dark fur.
- Fungal Culture: Samples are cultured to confirm the fungus and identify the species. Cultures may take over ten days and can yield false negatives.
- PCR Testing: Detects fungal DNA, allowing swift diagnosis, but doesn't differentiate live fungi from harmless remnants post-treatment.
- Biopsy: Sometimes, uncharacteristic lesions necessitate a skin biopsy for conclusive diagnosis.
Treatment Strategies
Oral Medication
- Itraconazole: Highly effective, especially in the oral suspension form for cats.
- Terbinafine: Newer, inexpensive, and effective when administered with food.
- Griseofulvin: Traditional but can cause severe side effects and is not suitable for FIV-positive cats.
Topical Treatment
- Lime Sulfur Dip: Used twice weekly, stains clothing, and has a strong odor.
- Miconazole-Chlorhexidine Rinse/Shampoo: Effective against spores; application frequency is crucial.
Environmental Decontamination
- Vacuuming and steam cleaning are essential, followed by bleach (1:10 dilution) application on bleach-safe surfaces.
- Hardwood floors benefit from daily electrostatic wipes.
- Monthly pet cultures guide progress.
- Infected pets should be confined until cleared, and all pets must be tested.
Persistent Outbreaks – What to Do
- Switch to fungal culture for diagnosis.
- Ensure adequate dipping frequency.
- Confinement of infected pets is vital.
- Consider immune system health and control secondary diseases.
- Use high-quality prescription antifungals.
- Verify the initial diagnosis.
For those affected, consult a medical professional for human infections. Remember, proper diagnosis and comprehensive treatment are keys to overcoming the ringworm challenge for both your pets and your home.
Don't have a vet in your area yet? We can help you find a local veterinarian.
If you have more questions, the GeniusVets Telehealth platform will give you unlimited access to text and/or video calls with board-certified veterinarians! To learn more click here.