Genetics And Breeding Strategies:
Essays For The Dog Breeder
By Dr. Susan Thorpe-Vargas
Reprinted with permission.
Dog breeding moves to the next level
Why the dog opted to share his fate with man may never be known. I suspect it had something to do with filling his stomach, but when he did so, mankind took on a moral and ethical obligation. When individuals started to selectively breed dogs for their own ends, their responsibility increased. How have dogs done under our stewardship? It seems that in many cases we have "improved" Canis familaris into a genetic nightmare. Today we have purebreds with a multiplicity of health problems that affect the quality and longevity of their lives while simultaneously sending the cost of dog ownership skyward!
Many people believe that an excess concern for cosmetic attributes has produced beautiful dogs that may get lost at the end of the leash. Today we have many breeds of "designer" dogs have been created through selective breeding that cannot whelp freely or breathe correctly. Every year billions of veterinary dollars are spent ameliorating the effects of this tampering. Is it too late? For some breeds it may be. If they were a wild species, certain breeds of dogs would be on the endangered list. That is why I have written these essays. If you are a breeder, I want to make you aware of the latest information on genetics, what you can do to avoid health problems, and screening technology. If you are a purebred dog enthusiast, this information will help you understand the awesome challenges breeders face.
I believe that anyone who loves his or her breed needs to know more than rudimentary genetics. The modern dog breeder should keep abreast of the very latest information available and take advantage of recent technological advances. What if you could screen your dog for all sorts of genetic diseases, or double up on the probabilities of a trait's expression of a behavioral trait such as the herding instinct or scenting? Even though the technology has not yet reached this stage, it is coming. With the human, canine, porcine, mouse and other genome projects under way, the breeding game has now progressed to the next level. Only breeders - each, acting individually - can address these problems.
Some of this material may be heavy going, but persevere. If your eyes start to glaze over, put the book down for a bit... and then pick it up again. The basics of genetics will be covered as well as such diverse subjects as the origin and domestication of the dog, a mini primer on Population Genetics, the techniques being used to discover the causes of genetic disease at the molecular level, and the tests currently available to breeders for genetic screening. I hope you will find this journey exciting and maybe it will encourage you to explore further.
Some of you question the need for such a book and ask yourself why it should concern you. Robert Jay Russell Ph.D., zoologist and breeder of Cotons de Tulear, put it succinctly1:
"Every breeder has the ability in a free society to "determine his or her own stopping point." But, a single breeder's actions may have consequences that are far-reaching. A breed is necessarily maintained by a society of breeders. As such, the actions of each breeder affects the actions of every breeder who dips their brush in the gene pool and every buyer - present and future - who buys one of these 'works of art.' Pragmatically (and ethically), a breeder loses his/her right to independence and his/her ability to be independent the minute he/she puts up a shingle that says 'Puppies for Sale.' "
About myself: I thought the best way to start was to talk about my own personal experience with breeding and my relationship with other breeders and "puppy people." All of us "in dogs" started somewhere, and not all of us had the good fortune to grow up in families that were well dogged and involved in breeding, show or other dog activities. My first Samoyed (my first ever dog) was a rescue but my family immediately fell in love with the breed and wanted their very own puppy. We had never had a puppy before and were not dog people. The people we got from rescue had a Christmas litter so we bought a bitch puppy from them as a present for my son. These people were one step up from backyard breeders as they did do some showing and they did do "rescue," but they had litters to make money. This Christmas puppy, call name Shisu, turned out to be my "foundation bitch" and I was extremely lucky with my choice, only I didn't realize it at the time. Shisu came into heat three times between six months and a year old. My vet told me either to breed her or fix her as this "girl wanted to be a mother." So, I called Shisu's breeder who said, "I have the perfect choice for a stud, you should breed her to her grandfather." So we did. The litter decided to arrive on Thanksgiving Day and the first puppy was breech. With my vet on the phone, I was walked through the process and was able to help Shisu deliver nine puppies, one of who later died. (We think the mother stepped on her) At six weeks, I put an ad in the paper and sold the puppies to whoever had the money. To this day, I have no idea what happened to those puppies.
What's wrong with this picture?
- The people who sold Shisu to me should have never sold a puppy at Christmas time. Leaving her mother and littermates was probably that puppy's or any puppy's most traumatic experience of her/their life. All the turmoil and confusion associated with the holidays is not an environment conducive to introducing a puppy to a new household, especially a family that had never had a puppy before.
- I had no experience with young dogs, and did not know what questions to ask. Knew nothing about the breed-hadn't done my "homework" and the breeder had done no genetic testing of her dogs.
- I bred a dog that was too young and had had no genetic testing done. Did not know what were the genetic diseases common in her breed and what, if any testing was available.
- I did not carefully plan the litter, studied no pedigrees, used a sire that was to closely related, and had not undergone any genetic clearance.
- I was neither physically nor mentally prepared to help whelp the litter, nor did I have the proper equipment, i.e., a whelping box with pig rails. I should have had an experienced breeder with me or at the very least, assisted at a few whelpings. I put both my mother dog and her puppies at risk because of my inexperience. Fortunately, Shisu turned out to be a very good mother, but what if she hadn't?
- I did not have a list of qualified puppy buyers prior to the breeding of her bitch.
- I placed her puppies through an advertisement in the paper. Did not require even the most basic criteria of my puppy buyers. I did not offer any guarantees nor did I have a puppy contract. One point in my favor: I did not sell her puppies to a pet store.
- I let those puppies go out in the world with no help offered to the new owners nor anyway to keep track of them.
I did not breed again for four years. I did a much better job the next time.
I learned that if you are a dog breeder, the purpose of having a litter is to provide yourself with a dog that you feel will better the breed, or at least maintain a high status quo with the best. However, every puppy you produce is not a show/performance quality dog. If you do not recognize this, then you are seriously deluding yourself. A side effect of producing your next show or performance dog is that you will always have pet quality dogs to place. Your responsibility to them is just as significant as it is for the dog/s you are keeping for yourself--maybe even more so. One should breed only dogs that have good temperament and good health. Again I have an example of what not to do:
I bought a bitch puppy from a very well known kennel that matched the phenotype of what I wanted to breed. This girl came from a litter of six, but only two survived. (Warning bells should have been ringing here.) After this girl reached two years of age and had passed her hips and eyes exams she was bred to a dog that was related to her seven generations back. She produced eight healthy puppies, all of which survived. She, however, developed eclampsia. Eclampsia is a life threatening condition involving an imbalance in the blood calcium levels. She was pulled through this situation but shortly after weaning her pups she started to get seriously dog aggressive. This behavior only worsened when I started to show her again and she became useless on the sled team. When I complained to the breeder, I was told to return her, and we did. Within a year of returning her, this dog had finished her championship and had been bred to her father. Her breeder obviously had no moral dilemma but I believe what she did was unethical. This girl should never have been bred again. Her life was put in jeopardy by whelping for a second time and such close inbreeding practically guarantees an increased probability that she would pass her poor temperament on to her offspring.
Regardless of the moral stances taken, it seems to us, there is a very real responsibility to breed carefully to avoid creating a cadre of genetically sick dogs. Registries will be forced by population genetics realities to modify their views of what constitutes purebred dogs. Breeders need to rethink their understanding of the benefits of line breeding and other such tight inbreeding schemes in favor of assortive matings to preserve genetic diversity. Those involved in breeds with few founders will run up against genetic reality sooner than some others. There is near certainty that there will be a day of reckoning where the genetic choices made in the past will determine the dogs of the future.
NOTE: Words that are in bold type when they first appear are in the Glossary.