However, according to the AAEP, congenital defects should not fall in the same category. They once were thought to be entirely genetic in origin, but now knowledge indicates that "many, if not most," such conditions are "the result of intra-uterine events that result from extra-uterine influences," including viruses and toxins. Examples of congenital defects include contracted flexor tendons in newborn foals, arthrogryposis, and cerebellar hypoplasia.Inherited tendencies, which include characteristics such as size, power, color, and speed, are genetically influenced. But their surgical correction should be allowed because while "variations from ideal may be undesirable, but they not genetic defects," the AAEP said. An exception is when a variation "has been specifically named by a breed organization as being prohibited." One example given by the AAEP was coat color. In such a case, performing a surgical procedure to correct the variation would not be ethical "because it has no benefit to the (health of the) horse and is intended only to deceive the breed organization," the AAEP said.In general, the AAEP "supports surgical correction of diseases that are in the best interest of individual horses."
The American Association of Equine Practitioners (AAEP) issued a statement in early March about its stance regarding genetic defects and their treatment. The action was taken after the American Veterinary Medical Association (AVMA) recently re-stated a policy that surgical correction of genetic defects for the purposes of concealing the defects is unethical. The AVMA also said if surgical correction is undertaken for the purpose of improving the health of the individual animal, then it should be accompanied by sterilization to prevent the perpetuation of the genetic flaw.The AAEP agreed with the intent of the AVMA statement, but said "it should be applied to genetic defects and not misapplied to congenital defects or inherited tendencies."In explaining its position, the AAEP said a genetic defect is "defined as a pathologic condition of proven genetic origin." According to the AAEP, the gene responsible for inheritance is known for only three genetic defects in the horse: hyperkalemic periodic paralysis in the Quarter Horse; lethal white syndrome in the Paint Horse; and combined immunodeficiency in Arabians. "If these conditions were correctable surgically, which they currently are not, their correction should be accompanied by sterilization," the AAEP said.