Congenital Defects Commonly Seen in Camelids

David E Anderson, D.V.M., MS, Diplomate ACVS
College of Veterinary Medicine
The Ohio State University, Columbus, Ohio

Congenital defects are a relatively common occurance among camelids. The high prevalence of congenital defects has been blamed on the narrow range of genetic diversity available to breeders prior to the importation of native South American stock during the 1980's. Despite the infusion of a presumably broad genetic pool from South America (primarily Peru) and rigid veterinary inspection of camelids prior to importation, congenital defects continue to be a problem for many breeders. The veterinarians role in counseling owners of camelids with congenital defects centers around the difference between congenital and heritable defects.

Congenital versus heritable defects

Congenital refers to a trait that an animal is born with (existing at the time of birth). These defects are not neccessarily genetically programmed and may have resulted from problems encountered during organogenesis or fetal development in utero (e.g. flexural limb deformity). Also, those defects that are genetically programmed in the fetus may not have originated from "heritable" defects. Heritable defects are genetically programmed in that animal and can be passed on from the affected animal. However, there are two options for genetic defects: 1) a point mutation in that animal but not preexisting in the parents and 2) a genetic defect carried by one or both parents and transmitted to the offspring.

References

1. Fowler ME. Congenital / Hereditary conditions. Fowler ME (ed), Medicine and Surgery of South American Camelids. Iowa State University Press, 1989.
2. Leipold HW, Hiraga TH, Johnson LW. Congenital defects in the llama. Johnson LW (ed), Update on Llama Medicine. Veterinary Clinics of North America, 1994.