What is the best treatment for a stray cat suspected of having multiple ringworm infections?

Treatment of Ringworm Infections from Stray Cats

For suspected ringworm infections from stray cats, oral terbinafine 30 mg/kg daily for 2 weeks is the most effective treatment, showing a 92% complete cure rate with fewer relapses compared to other antifungals. 1

Diagnosis

• Direct microscopic examination: Collect skin scrapings or hairs from the affected areas and examine with potassium hydroxide (KOH) preparation to identify fungal elements 2
• Culture: Gold standard for diagnosis - collect samples from new lesions and culture on Sabouraud agar 3
• Wood's lamp examination: Can help identify Microsporum canis infections, though sensitivity is relatively low 3

Treatment Protocol

Systemic Therapy (First-line)

1. Terbinafine: 30 mg/kg orally once daily for 2 weeks 1

   • Advantages: Faster cure rate, fewer relapses than griseofulvin
   • Particularly effective for Microsporum canis infections from cats

2. Alternatives if terbinafine is unavailable:

   • Itraconazole: Drug of choice for feline-derived ringworm 3
   • Griseofulvin:
     • Adults: 500 mg daily (can be divided into 125 mg four times daily or 250 mg twice daily)
     • Children (>2 years): 10 mg/kg daily
     • Duration: 2-4 weeks for tinea corporis (body ringworm) 2

Topical Therapy (Adjunctive)

• Miconazole: Apply to affected areas twice daily 4
• Combination therapy: Miconazole with chlorhexidine is recommended for more extensive infections 3

Management of Source and Environment

1. Animal management:

   • Infected cats should be isolated and treated with both systemic and topical antifungals 3
   • Veterinary care should be sought for the stray cat if possible 5

2. Environmental decontamination:

   • Infectious arthrospores can survive in the environment for up to a year 3
   • Thoroughly clean and disinfect all potentially contaminated surfaces, bedding, clothing, and grooming tools 5
   • Wash all bedding and clothing in hot water with detergent 5

3. Hygiene measures:

   • Thorough handwashing after any contact with infected animals 5
   • Avoid sharing personal items with infected individuals 5

Special Considerations

• Multiple lesions: May indicate more extensive infection requiring longer treatment duration
• Immunocompromised individuals: Higher risk for severe or disseminated infection; may require longer treatment courses 3
• Zoonotic potential: Ringworm is highly contagious between animals and humans 6
• Treatment duration: Continue medication until the infecting organism is completely eradicated as confirmed by appropriate clinical or laboratory examination 2

Follow-up

• Clinical evaluation at 2 weeks, 1 month, and 3 months after treatment initiation 1
• Consider repeat culture if clinical signs persist
• Treatment should continue until clinical resolution and negative cultures are obtained

Prevention of Recurrence

• Maintain good personal hygiene
• Regular veterinary care for pets
• Proper husbandry practices for animals
• Prompt treatment of any new cases in household members or pets
• Environmental cleaning to eliminate fungal spores

Ringworm from stray cats is a significant concern due to its high transmissibility and zoonotic potential. The combination of systemic and topical therapy, along with environmental management, offers the best chance for complete resolution and prevention of spread to other individuals or animals.