Favus (Ringworm) In Chickens

Sometimes navigating your way through understanding chicken pathogens and illnesses can be tricky. For instance, the name roundworm is a bit misleading because they resemble long skinny elastic bands and don’t really look round unless you look at them closely. Their name refers to their cylindrical shape, compared to some other types of worms which are flat.

Then there is ringworm, which isn’t a worm at all, but a fungal infection skin infection also called favus (or White Comb). Microsporum gallinae is the most common species found in favus cases in chickens and turkeys. Other species can affect people and other mammals. It’s called ringworm because in people and other animals such as dogs it often manifests as a red, itchy circular rash that causes hair loss.

Favus first appears in chickens as white, powdery spots and wrinkled crusts with scabs along their comb and wattles. The tiny spores of the fungus reproduce in the dead outer layers of the skin and then spread to other areas of the head, causing the skin to thicken and appear crusty and scaly. It may also result in some feather loss around the head and neck.

In most cases, if the outbreak only involves the comb, overall health of the bird is not affected. The disease is self-limiting, and the comb heals after several months. In severe cases, or where feathered areas are involved, there may be permanent damage to the beak and eyelids or the bird may become emaciated and die. 

Transmission

• There is the possibility of transmitting favus between people and chickens – in either direction – but that’s not a common route of infection.

• It is spread through direct or indirect contact with other infected birds, animals or people; soil, or fomites (inanimate objects such feeders, equipment, clothes).

Treatment

• Separate the infected bird from your flock in a DIY sick bay
• Treat with an over-the-counter topical fungicide such as Miconazole, Tresaderm, Panalog, Betadine or similar powder, ointment, or cream applied topically to the affected areas.

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Credits: Dr Vicki Bowes; Merck Veterinary Manual; Poultry DVM. Featured photo credit: Wikimedia Commons