February 19, 1990
Purdue Research Helps Large Dogs Survive Stomach Disorder
West Lafayette, Ind. Purdue University researchers have found a treatment that may improve markedly the survival rate of large- and giant-breed dogs that suffer from a particular stomach disorder.
Dogs such as Great Danes and Saint Bernards often experience gastric dilatation-volvulus, or bloat, in which the stomach unexplainedly expands and twists, reducing blood return to the heart. Under conventional treatment, which involves treating for shock and surgically repositioning the stomach, the dogs die about 40 percent of the time.
But a treatment developed by Drs. Gary C. Lantz and Stephen F. Badylak has increased dramatically the survival rate of dogs with bloat.
Lantz and Badylak have been studying bloat for more than two years. They say they believe they're the first to determine that death from bloat may be caused primarily by reperfusion injury rather than the initial shock.
Reperfusion injury is a chemical damage that occurs when oxygen-rich blood is restored to tissues that had been deprived of blood. In the case of bloated dogs, blood return to the heart -- and, therefore, blood pumped from the heart -- is decreased when the dogs' stomachs twist. When blood flow is re-established and the oxygen-rich blood comes in contact with blood-starved tissue, poisons -- or toxic oxygen radicals -- are released.
"It's a catch-22 situation," Lantz, professor of surgery in Purdue's School of Veterinary Medicine, says. "The tissues need the blood flow to be re-established, but yet in doing so these radicals are released into the body, resulting in reperfusion injury."
The researchers say their studies have shown that the key to increasing the dogs' survival is not only treating the dogs for shock but also injecting one of two particular drugs.
The drugs are deferoxamine and lazaroid, each of which minimizes or prevents reperfusion injury when appropriately administered, Lantz says.
Lantz says either drug will help dogs with bloat recover. Beginning in April, a two-year national study involving clinical trials of the two drugs at 10 veterinary medical schools -- including Purdue's -- will begin. Dogs with bloat that come to the veterinary clinics will randomly receive one of the following treatments: standard treatment, which involves giving fluids for shock and doing surgery to untwist the stomach; standard treatment plus deferoxamine; or standard treatment plus lazaroid.
"It will be a double-blind study because neither the medical personnel nor owners who consent to have their dogs in the study will know which treatment is given until after the study is over," Lantz says.
Lantz says, to his knowledge, this is the first large-scale clinical study on reperfusion injury and could provide knowledge on how better to treat other kinds of shock in animals and possibly in people.
The study will be funded by the American Animal Hospital Association and the American Veterinary Medical Association.
About 60,000 dogs in the United States develop bloat each year, and 40 percent of them die. Symptoms include dramatic swelling of the abdomen, attempts at vomiting and difficulty in breathing. Death occurs anywhere from one to several hours after onset.
Although the Purdue researchers say they don't know what causes bloat, they are hopeful that the national study will dramatically decrease the number of dogs that die from it. They say they also hope that using deferoxamine or lazaroid will reduce the many complications that can happen after surgery to untwist the stomach, such as intestinal, liver and heart damage.
"Complications are significantly reduced in other organs if dogs are given either of these drugs," Lantz says.
Other veterinary medical schools participating in the study are at the universities of Florida, Minnesota, Missouri, Tennessee and Wisconsin; and Kansas State, Louisiana State, Michigan State and Ohio State universities.
Lantz has a doctor of veterinary medicine degree. Badylak, who has a doctor of veterinary medicine degree as well as an M.D. degree, is an associate research scholar with Purdue's Hillenbrand Biomedical Engineering Center.
Note: Dr. Gary Lantz will be at the Fairmont Hotel in New Orleans Feb. 20-23 to present a report on this research Friday (2/23) at the annual meeting of the American College of Veterinary Surgeons. The following story is the result of an interview done prior to the meeting. The phone number for the hotel is 504-529-7111.
Purdue News Service: (765) 494-2096; firstname.lastname@example.org