The chronic form occurs in mature birds. Dystrophic (abnormal) feathers stop growing shortly after emerging from the follicle, and there number increases with each successive molt. The powder down feathers typically are the first affected. The disease will progress to other feather classes on the body.
The acute form usually occurs in young birds during their first molt, which replaces their neonatal down. Feather abnormalities are characterized by sudden alterations in developing feathers including hemorrhages, necrosis, fractures, bending, or premature shedding of diseased feathers.
Many of the affected birds may suscumb to acute bacterial & or fungal infections before any feather abnormalities are noted.
Testing is by DNA analysis of blood samples or tissues.
There is no known treatment
