May 20, 2010
The Purebred Paradox, Part 2
Is the quest for the "perfect" dog driving a genetic health crisis?
This year’s Westminster champion, a Scottish terrier named Sadie, hails from one of these tiny gene pools and is “very heavily inbred,” says Burns. The limited ancestry for AKC-registered Scotties, he adds, helps explain why 45 percent die of cancer.
“We do not need to have a closed registry to keep a breed,” Burns says, pointing out that breeds existed long before there was an organization to track them. “We did not create the dogs we love in a closed registry system—we have only ruined them there.”
Some breeders would doubtless disagree with Burns on this issue. But the inherent difficulties of protecting the health of a breed within a closed registry are exemplified by a project undertaken by the Basenji Club of America, which has in the past requested that its stud book be opened temporarily to bring in healthier animals.
Genetic problems in registered Basenjis were detected in the 1970s, when many of the small curly-tailed dogs known for being “barkless” began suffering from hemolytic anemia. After a test for the disease was developed, breeders tried to protect the gene pool through euthanasia of affected dogs, says club president Sally Wuornos. But eliminating dogs with hemolytic anemia left a much smaller number of registered Basenjis. And many of the remaining animals now displayed a different problem, a kidney disease called Fanconi syndrome. By addressing one disorder, the breeders had unwittingly amplified another.
Instead of repeating past mistakes and culling Fanconi carriers, the club received the AKC’s permission to open the Basenji registry to dogs from countries with no AKC-accepted registry. Since then, Basenji lovers have brought dogs back from isolated areas in the Congo and successfully integrated these healthy animals into the breeding pool.
Obtaining such permission to bring in new genes is unusual. Many breeders and clubs employ less dramatic measures: They pair mates who are healthy. They keep dogs with known disorders out of their breeding stock. They insist on conducting available genetic tests.
Yet in spite of these efforts, purebred health problems have continued and in some cases worsened. While genetic testing has made precautionary measures possible for some breeds in recent decades, people have been breeding dogs for centuries. Much damage has already been done. The modern German shepherd provides a classic example: One of the breed’s primary disorders, hemophilia, is thought by most experts to have spread almost entirely through the descendants of a single popular stud dog born in 1968 in Europe.
The filmmakers interviewed the RSPCA’s chief veterinary adviser, Mark Evans, who noted that his group was extremely concerned about “the very high levels of disability, deformity, and disease in pedigree dogs.”
Though veterinarians learn about such problems in school and see them in their practices, even they are sometimes still surprised by their prevalence. When veterinarian Paula Kislak adopted retired racing greyhounds, she assumed the breed “at the very least was physically strong because it was being bred for athleticism,” she says.
But because many racing greyhounds are killed when they cease performing on the track, few people knew of their genetic issues. As her dogs aged, “they were getting some really serious conditions in a proportion that was much higher than … the general population,” says Kislak, a member of the Humane Society Veterinary Medical Association’s leadership council. “The oncologists were seeing a lot of osteosarcoma. In fact, 50 percent of the greyhounds I’ve had have died of some sort of cancer.”
A Shot Across the Bow
While pet owners have been dealing with these issues relatively quietly for decades, the documentary Pedigree Dogs Exposed recently brought them to the forefront.
Broadcast in the U.K. in 2008, the film was critical of the Kennel Club, the British equivalent of the AKC, and showed purebreds with a range of health problems. Among its revelations: The 2003 champion of Crufts, the country’s most prestigious dog show, was a Pekingese who had to be photographed sitting on ice blocks because his flat face made him so prone to overheating. The film showed images of certain breeds in the early 20th century alongside pictures of the same breeds today, demonstrating how a century of selecting for looks had lengthened the back of the dachshund, rounded the skull of the bull terrier, and dropped the hindquarters of some German shepherds into an almost froglike stance.
The filmmakers interviewed the RSPCA’s chief veterinary adviser, Mark Evans, who noted that his group was extremely concerned about “the very high levels of disability, deformity, and disease in pedigree dogs.” According to the documentary, sickly purebred dogs were costing British owners 10 million pounds a week in veterinary fees.
In response, the Kennel Club and the Dogs Trust—a charity that, along with the RSPCA, had been critical of the club’s policies—jointly commissioned an independent inquiry led by Cambridge University professor emeritus Sir Patrick Bateson. The resulting report largely confirmed the documentary’s findings, concluding that inbreeding, selecting for extreme characteristics, and the practices of mass breeding facilities known as puppy mills were negatively impacting dog welfare.
Describing the tension at the heart of the issue, Bateson wrote, “To the outsider, it seems incomprehensible that anyone should admire, let alone acquire an animal that has difficulty in breathing or walking. Yet people are passionate about owning and breeding animals which they know and love, even though the animals manifestly exhibit serious health and welfare problems.”
Britain’s Kennel Club has since banned the registration of puppies from closely related parents (matings of fathers and daughters, for example) and revised many breed standards, adding language to emphasize health and soundness, says the group’s public relations manager, Heidi Ancell.
Many of the standards, she says, were amended to ensure they don’t encourage extreme features. The Pekingese standard now specifies that a “muzzle must be evident.” The bulldog’s standard calls for a “relatively” short face, stipulating that pinched nostrils and heavy wrinkles over the nose should be severely penalized by show judges—who have in the past rewarded high marks for such features.
Some breed clubs have welcomed the changes; others have protested. But in the United Kingdom, at least, there seems to be momentum for change. Whether that momentum will gather steam in the U.S. remains to be seen.