Similarities between dogs and humans, especially when it comes to genes, are also the basis for Dr. Matthew Breen’s research into the most common cancer in dogs, non-Hodgkin’s lymphoma, at NCSU’s College of Veterinary Medicine. Breen and fellow researchers have, with help from the canine genome map, developed a test that can accurately predict how long a dog treated with chemotherapy will remain in remission. In collaboration with the Mayo Clinic and others, they’re in the process of converting the canine test to a human one.
“If that happens, it will be big news,” says Breen, a geneticist and professor of genomics. Breen lost his first dog to cancer when he was 12 and, as an adult, played a role in the mapping of the canine genome—a game-changing achievement that helped place dogs front and center when it comes to health research.
“It’s likely that we will learn more about cancer by looking at what happens in our dogs over the next five to 10 years than we will in the next 20 to 30 of looking solely at cancer in people,” he predicts.
But the key, he emphasizes, is looking at both at the same time.
“If we consider dogs as dogs, we’ll be able to do so much. If we consider people as people, we’ll do so much. But if we consider them both as mammals, and look at what’s common between them, we will find some intriguing answers.”
The possibilities extend well beyond non-Hodgkin’s lymphoma, and well beyond cancer. Dogs, long our antidote for loneliness, may hold the most promise of all animals when it comes to solving medical mysteries and curing what ails us.
“The answer to some of nature’s puzzles about genetics and disease,” Breen says, “has been walking right beside us for the last few hundred years.”
In reality, we’ve been turning to dogs for thousands of years, sometimes quite cruelly, to try to solve our human ills: from the time of Aristotle, who conducted experiments on live animals, and the era of Galen, whose second-century experiments earned him the title “the father of vivisection,” to the period of Pavlov, whose 19th-century experiments included severing the esophagi of living dogs to better study their digestion and, as a sideline, bottling and selling their gastric juices to the public as a cure for dyspepsia.
Many of the medical treatments we now take for granted were either discovered through the use of dogs or tried on dogs first.
In England during the 1600s, the first administration of medication intravenously was accomplished in a dog, via tubes and a pouch made of an animal bladder. In the 1920s, experiments on dogs led to Frederick Banting’s discovery of insulin. Banting and fellow researcher Charles Best surgically stopped the flow of nourishment to a dog’s pancreas and, after it degenerated, removed it, sliced it up, froze the pieces then ground them up. They named the extract “isletin.” When it was injected into another dog in which they’d induced diabetes, the dog’s blood glucose level dropped.
In the 1960s—long before they were ever slipped into clogged human arteries—stents were inserted into those of dogs. When a ballooning version was developed in the 1980s, it too was first tested on dogs.
Currently, as humans wait to take full advantage of its purported promise, stem-cell therapy is becoming more common—though expensive, at around $2,500 per treatment—in treating dogs with arthritis, hip dysplasia and spinal-cord injuries. Removing, treating and reinjecting stem cells (and even differentiated cells) have led to some miraculous recoveries.
Dogs may have access to novel cures and treatments yet to be made widely available to humans, but there’s a trade-off. They are still, in a way, being used as guinea pigs. The difference is—compared to Pavlov’s day, compared to some of the unsavory experimentation on dogs that still goes on—they’re not healthy dogs, or dogs in whom diseases have been induced. Most often, they’re patients, sick dogs who have run out of alternatives and whose owners have enrolled them in clinical trials in hopes of, if not curing their own pet, furthering research that might help other dogs.
The canine cancer samples from around the country that end up in Breen’s lab come from willing donors, or at least willing owners, many of whom see contributing to such research as a way their dogs can leave a lasting mark.