Chmielewski N T, Render J A, Schwartz L D, Keller W F, Perry R F
Angell Memorial Animal Hospital, Boston, Massachusetts 02130.
Avian Dis. 1993 Oct-Dec;37(4):1151-7.
In 1991, 69% of the cockerels and 15% of the pullets in an inbred flock of approximately 200 dark and light Brahma chickens had unilateral or bilateral cataracts and crooked toes. Affected chickens were normal at hatching but developed cataracts with or without crooked toes by 6 months of age. The cataracts were initially focal and polar but progressed to be diffuse throughout the lenticular cortex. The crooked toes involved one or more of the second, third, and fourth digits and were due to a medial deviation of the distal aspect of the first phalanx. The cataracts and crooked toes were considered likely due to a hereditary defect, based on the following: the history of flock inbreeding; the lack of historical, clinical, or pathological evidence of avian encephalomyelitis or Marek's disease; the presence of lesions only in Brahma chickens and not in the approximately 200 other chickens on the farm kept under the same management and environmental conditions; the age at which the lesions occurred; and the nature of the lesions.
1991年，在一个约有200只深色和浅色婆罗门鸡的近交鸡群中，69%的公鸡和15%的小母鸡患有单侧或双侧白内障以及脚趾弯曲。受影响的鸡在孵化时正常，但到6月龄时出现有或没有脚趾弯曲的白内障。白内障最初为局限性和极性，但发展为整个晶状体皮质弥漫性病变。弯曲的脚趾涉及第二、第三和第四趾中的一个或多个，是由于第一指骨远端向内侧偏斜所致。基于以下几点，白内障和脚趾弯曲被认为可能是由遗传缺陷引起的：鸡群近亲繁殖的历史；缺乏禽脑脊髓炎或马立克氏病的历史、临床或病理证据；病变仅出现在婆罗门鸡中，而在农场中处于相同管理和环境条件下饲养的约200只其他鸡中未出现；病变出现的年龄；以及病变的性质。
