Favus is a fungal infection affecting the skin and feathers of chickens, caused by dermatophytes. Unlike other common poultry conditions, favus is contagious to humans and requires careful handling and hygiene protocols. Early identification and prompt treatment can prevent spread through your flock and protect your family’s health.
What it looks like
Favus manifests as visible lesions and changes to the bird’s appearance. Affected birds may display several or all of the following signs:
Circular scaly lesions on skin (Skin (head, neck, combs, wattles most commonly)): Round, raised, scaly lesions with a yellow crusty center and inflamed border
Feather loss and poor feather quality (Feathers and follicles): Feathers become brittle, dull, and fall out easily; new feather growth is stunted
Thickened, crusty skin (Affected skin areas): Skin becomes thick, dry, and covered with yellowish-brown crusts
Reduced growth (in young birds) (Overall development): Chicks with favus show poor growth, lethargy, and reduced feed intake
Pruritus (itching) (Affected areas): Bird scratches and pecks at lesions excessively
The most distinctive feature is the circular scaly lesions with a yellow crust, which gives favus its characteristic appearance. These lesions typically appear first on the comb and wattles, but can spread to any bare or sparsely feathered skin.
Likely causes
Favus is caused by dermatophyte fungi, with multiple factors contributing to infection:
- Infection with Trichophyton megninghitis or Microsporum gallinae (favic fungi)
- Direct contact with infected birds or contaminated bedding, feeders, perches
- Spores survive in environment for months; poor sanitation perpetuating infection
- Young birds and immunocompromised birds more susceptible
- Stress and poor nutrition increasing infection risk
The fungal spores that cause favus are remarkably persistent, surviving in the environment for months. This makes favus particularly challenging to eliminate from a flock without thorough environmental decontamination.
What to do
Treatment depends on the severity of infection and the number of affected birds:
Topical treatment: Topical antifungal creams or ointments (ketoconazole, miconazole) applied to lesions. Systemic antifungal medications (griseofulvin or terbinafine) may be needed for severe infections. Isolation of affected bird. Cleaning and disinfection of housing.
Systemic antifungals may be necessary for severe or widespread cases. Isolate affected birds to prevent spread. Maintain excellent biosecurity, including hand hygiene when handling infected birds. Change gloves between birds to avoid cross-contamination. Disinfect feeders, waterers, and bedding that have contacted affected birds.
Birds can take 3-6 weeks or longer to fully recover, depending on the severity and the treatment approach. Monitor treated birds closely for signs of improvement, and continue treatment for at least 2 weeks after lesions appear to be resolved.
When to see a vet
Consult a veterinarian if multiple birds are affected, if treatment is not showing improvement after 3-4 weeks, or if you suspect favus in your flock (zoonotic risk requires proper cause and handling). A vet can confirm the infection through fungal culture or microscopic examination.
Prevention
Primary prevention: Maintain clean, dry bedding. Remove infected birds promptly. Disinfect housing and equipment regularly. Quarantine new birds. Avoid overcrowding. Treat parasites and manage stress to boost immunity.
Quarantine new birds for at least two weeks before introducing them to your flock, and inspect them carefully for any signs of fungal infection. Provide proper nutrition, clean dry bedding, adequate ventilation, and minimize stress in your flock to support strong immune function. Avoid introducing birds from sources where favus is known to be present. If you show symptoms of ringworm after handling affected birds, seek medical attention immediately and inform your healthcare provider of the exposure.
Frequently asked questions
Is favus contagious to humans?
Yes, some types of favic fungi can infect humans (zoonotic). Children and immunocompromised people are at higher risk. Wear gloves when handling infected birds and avoid touching your face.
How long does favus treatment take?
Topical treatment may take 2-4 weeks to show improvement. Systemic antifungal medications take 4-8 weeks. Relapse is common even after successful treatment due to environmental contamination.
Can favus be completely cured?
Individual birds can recover with treatment, but reinfection is common if environmental spores persist. Aggressive disinfection of housing and equipment is essential for cure.
Should I cull birds with favus?
Culling is not always necessary but consider if infection is extensive, treatment is ineffective, or quality of life is severely reduced. Isolation and treatment are options if you wish to keep the bird.