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Created page with "==Introduction== '''Achromatosis''' ''aka'' '''the failure to lay down normal feather pigments''' is caused by a variety of '''nutritional deficiencies''' including '''choline'''..."
==Introduction==
'''Achromatosis''' ''aka'' '''the failure to lay down normal feather pigments''' is caused by a variety of '''nutritional deficiencies''' including '''choline''', '''lysine''' and '''riboflavin''' deficiencies.

==Signalment==
A '''lysine''' deficiency during growth causes achromatosis in '''dark breeds of chickens''', '''turkeys''' and '''quail''', but not in rock doves or cockatiels. Achromatosis is caused by a '''riboflavin''' deficiency in '''growing cockatiels'''. '''Choline''' deficiency during growth can also cause achromatosis. In all these cases, birds moult and grow normal feathers some time after the phase of rapid growth is complete.

The major significance of achromatosis is as a '''serious sign of an underlying nutritional deficiency'''. Unlike signs of some other deficiencies, it is not dependent on the severity of the deficiency except in extreme cases where the feathers may not grow at all.

==Diagnosis==
Diagnosis of achromatosis is possible on '''physical exam''', however this should initiate an investigation into potential nutritional deficiencies.

==Treatment==
The proper course of action is to '''supply the limiting nutrient''' and, if the bird is still growing, '''observe growing feathers for normal pigmentation'''. When growth is complete, a reduction in nutrient requirements occurs. This reduction in requirements may allow a diet inadequate for growth to serve as an adequate maintenance diet, allowing the bird to produce normal feather colours. In this case '''no treatment''' is required.

==Prognosis==
Prognosis is '''good''' if the underlying nutritional deficiency is addressed, or the rapid growth phase ends (reducing the nutritional requirements of the bird). The birds will moult and grow normal feathers.

==References==
Forbes NA & Altman RB (1998) '''Self-Assessment Colour Review Avian Medicine''' ''Manson Publishing Ltd''

[[Category: To Do - Siobhan Brade]]
[[Category:To Do - Manson review]]
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