Congenital Syndrome of Anophthalmia-Microphthalmia with Associated Defects in Cattle

Abstract

An anophthalmia-microphthalmia syndrome occurred in 26 animals from several dairy and beef cattle breeds. Fifteen were bilaterally anophthalmic, 6 unilaterally anophthalmic, 3 microphthalmic in 1 eye and anophthalmic in the other, 1 bilaterally microphthalmic, and 1 unilaterally microphthalmic. Ten calves had other abnormalities involving the caudal portions of the spinal column including taillessness. Five calves were dissected and the contents of the orbital cavity and optic nerve examined macroscopically and microscopically. The sphenoid bone was malformed and the optic nerve vesicle-like. The remnants of ocular structures were histologically variable. The etiology of these defects in cattle is unknown.