By Jim Schutze
By Rachel Watts
By Lauren Drewes Daniels
By Anna Merlan
By Lee Escobedo
By Eric Nicholson
Over the last two years, scientists at the University of Texas Southwestern Medical Center at Dallas have purchased 63 dogs for use in federally funded experiments that began as far back as 1988. The canines, mostly foxhounds and mongrels, are trained to run on treadmills, and are then anesthetized for pneumonectomies, a surgical procedure in which one lung is removed.
One month later, after the dogs recover from surgery (which removes anywhere from 45 percent to 68 percent of their lung capacity), they resume treadmill exercise. But first, they are fitted for special masks linked to machines that monitor their breathing. Their workouts are observed for a year or more. Eventually, the dogs are killed and their lung tissue is studied.
What's the point of all this? A staff of 10 researchers at UT Southwestern, one of the country's top academic medical centers, says the experiments helped them become the first scientists to demonstrate that dogs naturally regenerate lung tissue and even restore normal lung function after pneumonectomy (a claim others dispute). Now, they are studying whether this tendency can be reproduced in humans and say more experimentation is needed to better understand the phenomenon.
"At present, the only definitive treatment for patients with advanced lung disease is lung transplantation," according to summaries provided to the Dallas Observer by UT Southwestern after a request under the Texas Public Information Act. "In light of the chronic shortage of donor organs and the severity of long-term transplantation-related complications, the search for other treatment options is imperative."
But UT Southwestern's canine experiments, led by physician Robert Johnson (who declined to comment to the Observer), have not gone unopposed. Animal activists have mobilized locally to protest the experiments as cruel and unnecessary. At a recent "Bark-a-thon" in late February, 60 protesters with 30 pet dogs in tow picketed the medical center during rush-hour traffic.
The research hospital didn't back down, but responded with a statement defending animal research as crucial to "virtually every major breakthrough in human and veterinary medicine in this century." The hospital, according to the statement, also reviews experiments for scientific validity and abides by federal, state, and local laws "to ensure [research animals] are treated as compassionately and humanely as possible."
More specifically, spokesman Phil Schoch says, researchers for the $200,000-a-year project wanted to see why dogs recover well after losing a lung, while humans wheeze and gasp. "Even with one lung, these dogs could still outrun the best Olympic athlete," he says.
Dogs make better recoveries, Schoch says, because their remaining lung expands to fill up open space, a condition that doesn't occur in humans because of thick tissue separating the lungs. The researchers are working with surgeons to see whether such tissue can be trimmed in humans; they are also studying regenerative drugs. "These animal studies lay the essential foundation for the clinical development of any promising new drugs," Schoch says.
Activists aren't impressed and promise to keep up the pressure. "I can't imagine having my chest cut open, having 68 percent of my lungs removed, having part of my teeth cut off, being fit with a heavy mask, and being forced to run on a treadmill," says Susan Oakey, vice president of Animal Connection of Texas. "I can't imagine the distress that would cause."
Rick Hamlin, a Garland veterinarian who runs the Kindness Small Animal Hospital, has reviewed the researchers' journal articles and also takes a dim view of the experiments.
He scoffs at the hospital's assertion that "there are no signs of discomfort" by the dogs post-surgery because of pain-reducing drugs. "I find that to be quite incredulous," says Hamlin. Long-term pain, he says, "is just in the nature of a thoracotomy," a term that denotes the opening of the chest through surgery. "Whenever you crack the chest," he says, "it involves substantial pain."
Hamlin, who as a student at Texas A&M once "liberated" a research dog, also objects to the tone of the researchers' articles and abstracts. He complains they record the dogs' status "as if collected from a petri dish instead of from a living creature that is often referred to as our 'best friend,'" and has "a deep sense of love and compassion toward humans."
For the most part, however, opponents argue strenuously that the medical benefits yielded by hospital investigations don't appear to justify pain inflicted on the dogs. Hamlin argues that the experiments are not groundbreaking, but redundant, pointing to a 1973 article in the Journal of Thoracic Cardiovascular Surgery called "Regeneration of the Lung in the Dog."
And Neal Barnard, a medical doctor who heads the Washington-based Physicians Committee for Responsible Medicine -- a progressive health-care group that has fought animal testing nationally with some success -- calls the whole effort "patently ludicrous."
While UT Southwestern says "the dog closely resembles the anatomical and physiological characteristics of humans," Barnard says human behavior affecting the lung, which can be severely damaged by emphysema, chronic asthma, smoking, and asbestos, makes experimental lung removal in dogs suspect.
"You don't get one damaged lung and one healthy lung in humans," he says. "The other lung is damaged too, and the dog model doesn't account for that." However, the hospital says that cancer, drug-resistant infection, and life-threatening bleeding often lead to solo lung removal.