CONTROL OF CANINE GENETIC DISEASES
by Dr. George Padgett

Book review by Nancy Ann Schoch

Little did I know - some years back - that the seminar offered by the WHWTCA at Montgomery County on October 4, 1985, would have such a lasting impact on my Westies and me.

The setting was the Valley Forge Hilton, and the program consisted of a lecture, complete with a question and answer session, by Dr. George Padgett of Michigan State University. The topic was breeding practices and genetics. I attended, partly out of curiosity, but mainly because I was becoming painfully aware that I had a problem in my Westies' bloodlines.

For several years, nearly one-quarter of my pups had been born with cleft palates. As I searched for answers, I was told "Don't tell ANYONE you have a problem" and "Of course, my lines don't have that problem" and "Gee, it must be something in your environment"!

Listening to Dr. Padgett speak that evening, I was caught up in his enthusiasm and exceptional knowledge of dog breeding and genetics. His statement: "You CAN breed good dogs and breed out the defects" kept haunting me weeks after the seminar. So I contacted him for help with my problem; I was overwhelmed with his immediate enthusiasm. "Okay, let's see if we can find out if it is genetic!" Genetic pedigrees, test matings and several years of work spurred on by Dr. Padgett's infectious drive and humor proved that, indeed, my Westies carried genes for the polygenic cleft palate defect.

Not too many years ago, genetic disease and defects were a very unpopular subject. None of us wanted to admit to producing a pup that was not perfect, and many of us continued to breed our favorite bitches to the top-winning dog of the moment, never questioning the genetic integrity of these sires and dams. After all, if the owner proudly claimed that his Westie had NEVER produced "Disease X", we were confident that we had made the right choice in the breeding partners!

However, the 90s have brought new scientific breakthroughs in genetics - both human and canine - with the advent of the huge project of mapping the human and canine genome (a "genetic map"), location of marker genes and DNA testing. As our knowledge of genetics grows, we are increasing our ability to determine what genes, both good and bad, our dogs carry. As these tools become available to breeders, there will be absolutely no excuse for claiming ignorance as to whether our champion stud produces, for example, CMO. In fact, work is underway right now to find the CMO gene, and within a few years, it should be possible to test our breeding stock with a simple cheek swab and know unequivocally whether each and every Westie is positive or not for this disease.

It is refreshing to note that interest in canine disease is now becoming "fashionable". Much bad press (Atlantic Monthly, Time Magazine, Larry Shook's Puppy Report) has made the dog-buying public aware that purebred dogs are less sound and more disease-ridden than ever before. As buyers ask more questions of breeders, and more and more breed clubs establish committees to study diseases, and with the advent of the AKC Canine Health Foundation and our very own Westie Foundation, interest in discovering, preventing and eliminating genetic disease is at an all-time high.

Thus, Dr. George Padgett's long-anticipated book, "Control of Canine Genetic Diseases" (Howell Book House), published in October, 1998, could not come at a better time. Dr. Padgett is superbly qualified to write this book, having published more than two hundred scientific papers and having authored or co-authored publications that have established the mode of inheritance for thirty-two canine genetic diseases. He has also presented seminars and spoken on canine genetic diseases for almost two hundred national and regional specialty and all-breed clubs.

What sets this book apart from previous works of this ilk is that the major thrust is the control of canine genetic diseases by breeders and breed clubs. Dr. Padgett points out that national breed clubs have in their constitutions the goal to "improve the breed and bring its natural qualities to perfection", which means that you and I should make every effort to produce healthy, winning dogs. He states: "When you have finished this book, if you apply its principles, you should be able to do exactly that and so should your breed club." Historically, he points out, control of genetic disease was never part of the responsibilities of a breed club, so the vast majority has never done anything about it. Most of the seminars presented by breed clubs are on movement, or breeding a winning dog, or judges' education, or behavior, or effective training. He suggests that breed clubs add another dimension to their role - that of offering its members and breeders the tools to learn about, detect and discuss openly the various genetic problems occurring in that breed.

Westies have thirty-five genetic diseases, and in the survey done several years ago, the incidence of CMO was found to be 1.13%, Legg-Perthes 1.93%, and Hip Dysplasia 0.56%, totaling 3.62% for just these three diseases in all Westies produced annually. Both the Cairn Terrier Club of America and the Scottish Terrier Club of America have had the courage to survey their breeders, members and owners and found that genetic disease occurs in 40.3% of Cairns and 33.5% of Scotties. From the data reported, Dr. Padgett has determined that each Cairn carries 5.03 and each Scottie 4.7 defective genes.

Once Dr. Padgett establishes the premise of his book, he begins to teach us genetics, beginning with a chapter on constructing a pedigree, using symbols, not the names of ancestors. In true professional form, there is a test at the end of the chapter, asking us to draw the pedigrees of various dogs … and thankfully the diagrammed answers follow! His next chapter covers Modes of Inheritance - how traits are inherited - and he presents a methodology for breeders, not geneticists. Again, questions and answers follow the chapter.

As we progress through the book, we learn how to develop a genetic pedigree from the common buyers, or linear pedigree, and how to calculate probabilities - the percentages that a given dog will or will not produce a certain defect. We learn that test mating can be an extremely useful guide if done properly, and Dr. Padgett addresses questions of ethics in producing and selling puppies, which are products of such test matings.

Closed and open registries are explained: a closed registry releases information only on phenotypically (visible) normal dogs, i.e. OFA will certify hips graded as normal, but will not release any information on dogs tested who have bad hips. Open registries make all data available to breeders, whether the dog is phenotypically normal or affected with one or more diseases.

Chapter Eleven, "For the Breeder", is both brutally honest and a leading reason this book was written. Dr. Padgett uses a hypothetical Scottie bitch and two possible stud dogs, asking which stud would we choose? After reviewing their genetic status, it is concluded that all three top-notch dogs should NOT be bred. Padgett states: "Do you know now why people won't tell you about the disease status of their dogs? If you won't breed these dogs, what dogs will you breed? Currently, the way you handle this situation is to blacklist dogs like these three and breed to dogs whose owners lie to you … we do things in exactly the reverse order of how we should do them. We ostracize people who tell us the truth and give our trust (and our stud fees) to the people who are not honest with us."

The book concludes with two appendices, one listing three hundred eight dog breeds with reported diseases and defects for each, and the other describing four hundred thirty seven genetic disorders, divided into systems and cross-indexed by breed.

Whether you breed, show, are involved in performance events or enjoy a pet Westie, we urge you to read this book. Why, you ask? Even if you are not involved in active breeding, you are probably going to own another Westie, yet unborn, in the future. It is incumbent upon you to make certain that Westies are as disease- and defect-free as possible. This book will help all of us to come nearer to the goal of healthy, winning Westies. Dr. Padgett has created an extraordinary work: readable, honest, offering guidelines to solving some of the problems in our breed, and yet delightful to read with snippets of his mischievous humor!

Reprinted with permission by the author and the Winter, 1998 issue of the Westie Imprint.