[Nancy1999]

Originally Posted by jeanief

Genetic defect
The AVMA statement refers specifically to correction of genetic defects. By definition genetic defects are a pathologic condition of proven genetic origin. The gene responsible for inheritance is known for only four genetic defects in the horse: hyperkalemic periodic paralysis in the Quarter Horse, lethal white syndrome in the Paint Horse, combined immunodeficiency in Arabian horses (1), and hereditary junctional mechanobullous disease in Belgian horses (2). If these diseases were correctable surgically, which they currently are not, their correction should be accompanied by sterilization.

Congenital defect
All undesirable traits and pathologic conditions present at birth were at one time thought to be entirely genetic in origin. Present-day knowledge has evolved to the point that we now know that many, if not most, congenital defects are the result of intra-uterine events that results from extra-uterine influences. Viruses and toxins are well documented to cause congenital defects (3, 4). Certain conditions that were previously thought to be genetic are now suspected, with good evidence, to be created by viral or toxic insults. Contracted flexor tendons in newborn foals have been proven to be created by toxic influences in some instances (5). Arthrogryposis and cerebellar hypoplasia, are other diseases that have suspected infectious or toxic causes because this link has been proven in other species (3, 4). Congenital defects do not indicate inheritance; they simply indicate that the defect was present at birth.

Great post, I never understood the differences before.