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 infect other
areas, including the comb or wattles. The mite spends its
entire lifecycle on the birds and is usually spread by direct
contact.
Birds infected with scaly leg have raised or
protuding scales, sometimes with a white crusty appearance.
Scaly leg is extremely
irritating to the infected bird, and in extreme cases
can result in lameness.
The disease can be treated by soaking the afflicted
bird's legs in soapy water mixed with diluted ammonia, and
the encrusted areas scrubbed gently with a soft brush,
followed by the application of an insecticide to kill the
mites, usually oil based. Petroleum jelly (mixed with
sulphur if available), or a commercial chest rub can be used — the mites are unable to breathe
beneath the jelly.
Multiple treatments may be required to completely
eliminate the mite, and pen, perches, and
nesting areas should be sprayed. Ideally birds should be
moved to a new area for at least a month to avoid
re-infection from dropped scales that may remain infectious
for up to 30 days.
References