Genetic defects in domestic animals


Ratification Date: 01 Feb 2009


Animals with known genetic defects that have the potential to adversely affect their welfare or that of their progeny should not be used for breeding, other than in exceptional circumstances.


A genetic defect is a heritable trait that adversely affects an animal’s appearance, physiology or function.


People have been actively involved in the selection of preferred traits that enhance the functional value or the aesthetic appeal of specific animal breeds, while at the same time working to preserve and improve animal health and well-being. The ability to select for a specific genetic trait through controlled breeding has resulted in a remarkable variety of animal breeds that are both physically and functionally unique.

Artificial breeding techniques, such as embryo transfer and artificial insemination, have the potential to inadvertently accelerate the dissemination of genetic defects. Care must be taken to minimise this risk.

The development of workable government legislation is encouraged to minimise promulgation and dissemination of genetic defects in domestic animals, with the onus of responsibility being placed on the breeder or vendor of animals displaying or carrying the genetic defect.

In companion animals, where performance and production are not factors in breeding selection, many genetic defects have become prevalent. In many cases, these defects are not incompatible with survival and reproduction and, although undesirable, a few have been included in breed standards. Brachycephaly (a short or flattened face) and chondrodystrophy (dwarfism) are examples in several breeds of dogs.


The following guidelines should be observed with regard to genetic defects in domestic animals.

  • Animal breed societies and controlling bodies should be encouraged to instigate, support and recommend procedures to identify affected and carrier animals. Individual owners should not be targeted; instead, breed societies should be assisted to reduce the incidence of genetic defects.
  • Breeders should be encouraged to adopt strategies for minimisation of the breeding and dissemination of animals displaying or carrying genetic defects.
  • Individual animals affected by a genetic defect should be desexed or not bred. Some controlled breeding of affected animals under a recognised breeding program may be necessary to ensure genetic diversity in that breed.
  • Potential owners of animals should be advised of the problem and information provided to purchasers prior to sale.
  • Where a genetic test is available for carriers of an inherited defect, two recognised carriers should not be bred.
  • Breeding animals to be imported from other countries should be certified by the breed society as free from known genetic defects before they (or their genetic material) are imported.
  • Veterinarians should play an active role in identifying and monitoring genetic diseases and assisting breed societies and breeders with advice. They should also assist in the education of owners managing animals displaying inherited defects.

Other recommendations

Research should be carried out to determine the mode of inheritance and expression of particular defects.

Awareness of genetic disease should be encouraged as should practices and research to minimise its incidence and effects in populations of animals.

Date of ratification by AVA Board February 2009