This article is a collection of information presented at seminars by Dr. George A. Padgett, DVM. Dr. Padgett is a veterinary pathologist at Michigan State University with special interest in canine genetics and what role breed clubs play in the control of the genetic diseases in their particular breed. He cites the need for open record keeping which will report all evaluations (abnormal as well as normal) as being essential to health improvement in a colony of dogs or a breed as a whole. Dr. Padgett was one of the founders of the GDC which is this kind of registry.
Responsibilities of a breeder:
Should have established breeding goals for their line, defined by their ideal dog so they know what they are breeding for and can select an appropriate test mate.
Should have an established selection method to use in selecting the test mate.
Should have arrived at a hierarchy or degree of disagreeableness of traits known to occur in their breed which they can apply to their dogs (all may not involve the "health" of their dogs).
Should know traits that occur in their line and traits that potentially could occur in their animal or are known to exist in their animal.
Obligations of a breeder:
Register all animals that are known or potential carriers with an appropriate disease registry.
Test mate all offspring retained for breeding or sold as "breeding" quality in order to assure knowledge of the pathway of the gene in question.
Thoroughly explain to any purchaser of potential breeding stock that the defective gene may be present and what will be required to eliminate the gene. Do not imply that it is of no importance.
Thoroughly assure yourself and the breed that "pet quality" animals that will not be shown or used for breeding remain pets.
Require a spay/neuter agreement.
Do not issue papers until the animal is spayed or neutered.
Require a deposit, sufficient to pay for the spay or neuter, to be returned when evidence is presented that the surgery has been done.
Require that the spay or neuter be completed before the animal would be of breeding age (7-9 months).
Disagreeableness of Genetic Traits:
Disorders that cause pain to the animal (i.e. glaucoma, CMO, hip dysplasia, entropion, distichiasis, luxated patella, Legg-Perthes)
Disorders that disfigure, maim or otherwise render an animal nonfunctional (i.e. cataracts, retinal dysplasia and detachment, chondrodystrophy).
Disorders that require treatment for the life of the animal (i.e. Grey collie syndrome, diabetes, inherited hypothyroidism).
Disorders that require surgical correction for the animal to survive (i.e. esophageal achalasia, anasarca, ventricular septal defects).
Disorders that are difficult to control (i.e. multigene traits, abiotrophic traits).
Less disagreeable genetic traits
Disorders that require one time surgery that is highly successful and principally cosmetic (i.e. inguinal hernia, umbilical hernia, monorchidism).
Disorders that prevent an animal's use for the purpose for which it is bred (i.e. albinism, correct color, mild bite/dentition or gait abnormalities).
Expectation when using a known carrier for breeding:
In any scheme used to control genetic diseases in dogs one produces an equal number of carriers whether a test mating or a dilutional system is used.
In the process of detecting carriers in the general population of dogs using a random mating system, large numbers of carriers are produced.
The effect of outcrossing is to hide a gene, not to eliminate it.
Any breeding is in effect a "test" breeding if total records are kept. This allows one to benefit by retrospective breedings if the records can be assembled accurately and used in the accepted way to assign the risk that an animal has of being a carrier after producing varying numbers of pups.
Dr. Padgett recommends the paper, "What Do We Know About Hip Dysplasia Today?" by Lennart Swenson, Sweden, May, 1987 as the most significant report on hip dysplasia since the original 1935 report of HD in dogs by Schnelle.
We need to quit whispering about defects, and gossiping about defects, and instead set up a sound program that allows the standard selection procedures to go on so that we breed good dogs and avoid major defects.