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.
Barnard posits that human subjects could be used to study lung regeneration. For example, UT Southwestern is one of four institutions nationally using the Vitamin A compound of retinoic acid to further stimulate lung growth in dogs; Barnard says the substance could just as well be given to humans under experimental therapies.
"These people are trying to make a rationalization for these studies," says Barnard, who deems their funding better spent on preventive care. The real motive behind such studies, he charges, is attracting much-coveted research dollars to the university and getting articles published in scholarly journals.
This belief, strongly denied by researchers, has engendered its own slogan. "Doctors publish, dogs perish," as Susan Oakey puts it.
The treadmill exercises aren't the only canine experiments at UT Southwestern. Another team is examining how the brain processes information from receptors in skeletal muscles and major arteries, which activate during physical activity and send neural signals to the brain critical to controlling blood pressure. The experiments may help ease heart disease, Schoch says, and are conducted on dogs under full anesthesia.
Schoch says that goats, sheep, and worms are also part of other UT Southwestern experiments, but that rats and mice account for "99 percent" of experiments at the school, which counts more than 1,000 full-time faculty members.
While some groups have fought rodent experiments, arguing they are painful and difficult to extrapolate to human health matters, Animal Connection of Texas says it will focus on dogs first. In the meantime, the group, which successfully fought to end the practice of Dallas shelters selling strays to research labs, plans to continue its protests. Members once inundated Dr. Robert Johnson's neighborhood with fliers detailing the experiments, but some activists considered that tactic too militant, so they stopped it.
The group has also sought access to meetings of the hospital's Institutional Animal Care and Use Committee, a panel of faculty members that supervises experiments. Initially, hospital officials denied that state open-meetings laws applied to the panel, but they dropped that claim under threat of a lawsuit, according to Don Feare, an Arlington lawyer representing Animal Connection.
Controversy or not, Neal Barnard thinks animal testing is on the wane. He says his group has convinced many medical schools to cease animal lab experiments and succeeded in ending military "cat-shooting" studies, Drug Enforcement Agency narcotics experiments on animals, and monkey self-mutilation projects. Sophisticated analysis, in vitro research, and use of human cells are methods that are gradually replacing animal experiments, he says.
"We are getting better and better at using human patients," Barnard says. "We are seeing fewer and fewer of these crude animal experiments."
