Heritable Congenital Defects

Heritable congenital defects are being recognized at an increasing rate, but only a few are unequivocally propagated as a result of specific but unrelated trait selection. This chapter describes the fundamentals of report investigations, and morphologic characteristics, mode of inheritance, breeds affected, and availability of specific tests or anatomic hallmarks for select heritable bovine fetal abnormalities. The etiologies of congenital defects in cattle can be divided into heritable, toxic, nutritional, and infectious categories; distinguishing among different causes is essential in the management of the disease but may be challenging. Arthrogryposis multiplex (AM) is a lethal autosomal recessive genetic defect that originated in Angus cattle. Congenital contractural arachnodactyly, or “fawn calf syndrome, " is a non-lethal autosomal recessive genetic defect of Angus cattle. Neuropathic hydrocephalus (“water head”) is a lethal autosomal recessive genetic defect of Angus cattle. At the same time that AM calves were being submitted, calves with hydrocephalus were also submitted.