How Selective Breeding Hurts Dogs

By Joan Dunayer and Eric Dunayer, VMD

Reprinted with the authors' permission, October 2015

Originally published in Animal Guardian, Spring 1992, pp. 7-9, 15
Copyright 1992 Joan Dunayer and Eric Dunayer

By selling purebreds, breeders perpetuate the view that dogs are customized merchandise.

“We hold the animals real close and comfort them,” the euthanasia technician says while her assistant carries in a black puppy—frisky, round-eyed, with short floppy ears and a white chest. Wagging her tail, the puppy is placed on a stainless steel table. The assistant scratches her behind the ears and strokes her from head to tail. “She’s a good girl,” the assistant tells her, hugging her tightly. The puppy lifts her head and licks the assistant’s face. “She’s the best puppy,” the technician comforts as she injects sodium pentobarbital into the puppy’s forearm. “She’s just the best puppy.” The puppy blinks twice; then her eyes are blank. As the puppy goes limp, the two women gently lay her on her side. She is dead. The assistant lifts the body and cradles it in her arms. Quickly she gives the puppy a final kiss on the forehead. And hurries out. In the freezer room, the puppy’s body will join the others heaped inside barrels.
Annually U.S. shelters kill an estimated five to nine million dogs, two-thirds of those who enter. Along with the infirm, the sweet-natured and healthy die—because they are homeless.
Millions more homeless dogs suffer as strays, debilitated by wet and cold, vulnerable to skin-mites and worms, infected wounds and broken bones. Hunger compels them to scrounge through trash. They die not from the quick, painless flow of sodium pentobarbital but from disease, exposure, accidents, and abuse.
The breeding of purebreds directly contributes to dog homelessness. On average, one-fourth of shelter dogs are purebreds. At some shelters the number of purebreds periodically overwhelms that of mixed breeds; each January, 90 percent of the Kentucky Humane Society’s dogs are purebreds, mostly puppies given as unwelcome Christmas gifts. Tens of thousands more purebreds annually lose their homes but bypass shelters because they go directly to the foster care of breed-specific rescue groups. These groups, which also work to find permanent homes for shelter purebreds, number more than 1,500 nationwide. President of the Collie Rescue League of Metropolitan Washington since its inception in 1981, Martha Handman says, “We have never been able to help all the collies needing homes. Some are euthanized when our efforts fail.” Finding homes, she adds, is increasingly difficult.
Yet the unrestrained breeding of purebreds continues. Approximately 5,000 “puppy mills” annually breed over 500,000 purebreds for sale in pet stores. These puppies are mass-produced without any regard for their long-term health. Usually they are shipped at only six to seven weeks of age; many fall ill from the stress of transport. Robert Baker of the Humane Society of the United States has investigated hundreds of puppy mills and reported brutal conditions. Most females kept for breeding spend their entire lives in small, dirty wire cages—denied all exercise and companionship. Housed outside, the dogs endure the harshest weather extremes. They also lack adequate food and water. Baker has witnessed “thirsty dogs desperately pawing at drinking water that had turned to ice in the bowl.” Viewed solely as puppy machines, the females are bred every time they come into heat and killed at age five or six, when their “production” declines.
While the most notorious source of purebred dogs, puppy mills are not the largest source. In 1990 the American Kennel Club (AKC) received 2.8 million requests for dog-registration applications—a figure that does not encompass all purebred births and well exceeds the half-million total for puppy mills. Small-scale breeders such as hobby (show) breeders must, then, be responsible for the vast majority of purebred dogs.
Although show breeders deny culpability for dog homelessness, the homeless include many purebreds from their kennels. One shelter manager recently stated, “Almost 40 percent of the dogs at the Humane Society who need new homes are purebreds. I have here a stack of pedigree papers from dogs and cats given up to the Humane Society in just the last few months. These animals come from both private breeders and pet stores. Some come from champion lines. One is even a finished champion show dog.” As Martha Handman can document, at least 38 percent of the collies referred to her rescue group have originated with show breeders, and she believes the actual proportion is more than half. Show breeders, Handman notes, often produce many litters to support their hobby.
What about breeders who find permanent homes for all their dogs? They, too, contribute to dog homelessness. By selling purebreds, breeders perpetuate the view that dogs are customized merchandise, that it is more desirable to purchase a purebred than adopt a shelter dog, particularly a mixed breed. That view keeps puppy mills selling and shelters overflowing.
The very act of selective breeding harms dogs. So-called “responsible” breeders take pride in producing dogs whose looks conform to a particular “breed standard.” The AKC defines this standard as a “description of the ideal dog of each recognized breed,” an “attempt to describe perfection.” In reality, selective breeding impairs rather than “perfects” dogs.
Free of human manipulation, dogs tend to resemble the Australian dingo. An expert on canine ancestry, Dr. Michael Fox has noted the features that characterize the “natural” dog: weight of 35 to 55 pounds (the size of a Siberian husky); well-proportioned body; long, straight legs; medium-length muzzle; almond-shaped eyes; long, somewhat upturned tail; fully or partially upright ears; and short coat. Nature propagates these features, which promote health.
In contrast, selective breeding propagates disabilities. Unlike random mating, selective breeding commonly pairs harmful recessive genes—because the mated dogs are so genetically similar. As Dr. D. B. McKeown of Ontario Veterinary College has pointed out, “All purebred dogs are inbred to some extent.” Many dogs pass on an inherited defect before showing any signs of the defect, or without ever showing signs.
The majority of purebreds suffer from some inherited defect. Dalmatians, for example, are prone to deafness, poodles to epilepsy, boxers to malignant tumors, and Doberman pinschers to a bleeding disorder resembling hemophilia. Eye diseases plague purebreds—including cataracts, glaucoma, and retinal degeneration that ends in blindness. Among thousands of dogs studied by the University of Pennsylvania School of Veterinary Medicine, congenital heart disease afflicted purebreds at nearly 3½ times the rate in mixed breeds. On average, each breed of purebred dog harbors over a dozen genetic defects.
Selective breeding has undermined psychological as well as physical health. Toy dogs are frequently high-strung and hyperactive. Many mastiffs, German shepherds, and Dobermans are overly fearful. Some breeds, such as the shar-pei and chowchow, have a reputation for viciousness; others, such as the cocker spaniel, golden retriever, and Rottweiler, are acquiring this reputation.
In addition to perpetuating inherited disorders, breed standards prescribe numerous traits that are themselves pathological. One such trait is unnaturally large size, which reaches its extreme in the 200-pound mastiff.
Dr. Wayne Riser of the University of Pennsylvania School of Veterinary Medicine has noted a correlation between large size and orthopedic problems, which are rare in the natural dog. The greater the size beyond the natural dog’s, the greater the orthopedic risk.
Hip dysplasia, for example, most commonly affects large dogs. Chronically loose, the hip joints deteriorate, inducing a crippling arthritis for which there is no reliable cure. The breed standards for the St. Bernard, Newfoundland, bullmastiff, and German shepherd promote hip dysplasia by specifying heavy, broad hips—the feature that makes these breeds highly susceptible.
A deep chest—mandated for such large breeds as the Great Dane, Doberman, and German shepherd—predisposes a dog to gastric torsion. Bloated with gas, the stomach twists and the dog goes into shock. Among those dogs given emergency surgery, only half survive.
Large dogs have an overburdened heart, which frequently fails at an early age. Great Danes, St. Bernards, and Dobermans rarely live past age nine. In general, the greater a dog’s size beyond the natural dog’s, the shorter the lifespan.
Smallness, most exaggerated in the two-pound Chihuahua, also creates a special collection of orthopedic problems. In miniature poodles and other small breeds, abnormally restricted bone growth often leads to loose kneecaps that repeatedly dislocate. When a kneecap slips, the dog hobbles on three legs. Surgery may not correct the problem.
In tiny dogs such as the Chihuahua, skull size is dangerously reduced. The smallest dog has only 1 percent the body size of the largest dog, but 40 percent the brain size. As a result, the skull often fits the brain so tightly that spinal fluid within and around the brain cannot circulate freely. When the brain swells with the trapped fluid, the puppy’s skull grows in a domed shape to accommodate this disorder (hydrocephalus). If inadequate to encase the distended brain, the skull retains gaps—a condition called molera. Because hydrocephalus destroys brain tissue, affected dogs who survive into adulthood tend to be hyperactive, unresponsive to training, and in other ways mentally impaired. The Chihuahua standard encourages hydrocephalus by specifying an “‘apple dome’ skull, with or without molera.”
Some dogs are not small overall but have disproportionately small limbs. Leg and foot deformities virtually define such breeds as the basset hound and dachshund, which derive from the inbreeding of dogs afflicted with dwarfism.
The basset hound standard calls for short and thickened forelegs. Inevitably the legs bow, inviting chronic elbow dislocation. Similarly, the specification that the feet turn “a trifle outward” endorses a splaying that often results in lameness.
Truncated legs inadequately support the dachshund’s long, straight back. Consequently, about a fifth of dachshunds suffer ruptured vertebral disks, which cause excruciating compression of the spinal cord. Even with emergency surgery, many dogs remain uncoordinated in their hind legs, or paralyzed.
Whether or not they are bred for abnormal size, numerous dogs are bred to be brachycephalic (flat-faced). The bulldog standard decrees a nose “set back deeply between the eyes.” The effect is pathologically short and twisted air passages. Often an over-long soft palate further obstructs breathing. Brachycephaly shortens the bulldog’s life and reduces it to a ceaseless struggle against suffocation.
The breed standard for the Pekingese, another brachycephalic, dictates “prominent” eyes and a “wrinkled, very short and broad” muzzle. The combination often causes facial hairs to rub painfully against the cornea. In addition, the bulging eyes sit so tenuously in their sockets that a sudden jolt or blow to the head can dislodge them. Rapidly returning an eye to its socket rarely restores vision.
Breed standards prescribe numerous other harmful features. Long, floppy ears and deep, widespread wrinkling are only two examples. The cocker spaniel’s ears (the opposite of the natural dog’s) tightly cover the ear canals. Bacteria flourish in the canals’ moisture and warmth. Sometimes even cutting away an ear canal’s outer wall, for drainage, cannot eliminate chronic infection. Similarly, the shar-pei’s massive skin-folds often become furrows of infection. The folds also roll the eyelids inward, causing eyelashes and sharp, stubby facial hairs to scrape the cornea. Usually part of the eyelid must be surgically removed to prevent abrasions, ulcers, and scarring. Without such surgery, the dog will be blinded.
Breeders go to extraordinary lengths to maintain the most disabled breeds. Because the English bulldog standard demands a “massive” head and “relatively narrow” loins, virtually all bulldog births require caesarian section. Most bulldogs cannot even conceive naturally. The “perfect” bulldog, the standard says, has a low front and high rear—characteristics that hinder mating. For the dogs, breeding becomes an ordeal. Strap the female down or hold her by the legs, an article in the AKC’s official magazine advises. Then “assist” the male “in penetration.”
Often bulldogs must be artificially inseminated. As recently reported in a veterinary newsletter, the consequences can be disastrous: “Throughout the semen collection procedure, both dogs were very excitable and breathing with difficulty. After the semen was collected, the female dog was placed on her back for insemination. Her breathing continued to be labored.” When the dog began to struggle, she was restrained. Her breathing worsened. Still the forced breeding continued. Struggling to breathe, the dog died.
Although rarely this overtly cruel, selective breeding is always detrimental to dogs. Directly and indirectly, the breeding of purebreds increases dog homelessness. It also propagates genetic disabilities. Most insidiously, selective breeding fosters the attitude that a dog’s appearance matters more than his or her well-being. “If a dog isn’t the right type,” one AKC breeder has written, “he has no value to me.”
Like so many millions of other dogs, the brutalized bulldog and the euthanized puppy are breeding’s innocent victims.
Joan Dunayer is the author of Animal Equality: Language and Liberation (2001) and Speciesism (2004).
Eric Dunayer is a veterinarian and an Associate Professor of Veterinary Clinical Sciences at St. Matthew’s University.

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