Scaly leg is a disease of chickens and other birds. It is caused by a parasitic mite, Knemidocoptes mutans. The mite burrows under the scales in the bird's legs, but may also infest other areas, such as the comb or wattles of chickens. The mite spends its entire lifecycle on the birds and is usually spread by direct contact.
Birds infested with scaly leg have raised or protruding scales, sometimes with a white crusty appearance. Scaly leg is irritating to the infected bird, and in extreme cases can result in lameness.
In domestic birds the disease may be treated by application of an oily substance such as petroleum jelly, vegetable oil, or a commercial chest rub, thus preventing the mites breathing. Alternatively an insecticide may be used to kill the mites – or the two methods may be combined. The loose crusty scales may also be removed by soaking the afflicted bird's legs in soapy water mixed with diluted ammonia, and the encrusted areas scrubbed gently with a soft brush. Complete removal may take multiple treatments. Dropped scales may remain infectious for up to a month, and so pen, perches, and nesting areas may also be treated, or birds may be moved to different housing for several weeks.
- Poultry parasitic diseases, Mississippi State University
- Scaley Leg Mite (Knemidocoptes mutans) information page on poultrykeeper.com
- Moore, Alanna (1998). Backyard Poultry — Naturally, 2nd Ed. Bolwarrah Press, Bolwarrah Vic Australia. ISBN 0-9585590-1-5.