An additional one-third of the dogs might still be pets if their owners had sterilized them or had realistic expectations about the pet's behavior.
"Dogs that had not been in obedience classes were about 3.5 times more likely to be relinquished to a shelter," says Dr. Gary J. Patronek, a post-doctoral fellow in Purdue's School of Veterinary Medicine and one of the study's authors. "Dogs that hadn't been to the veterinarian at all were about 13 times more likely to given up than dogs that had been at least twice. Veterinary care and obedience classes may increase the owner's bonding to the dog."
The researchers calculated the potential reduction in number of dogs relinquished to shelters using a statistical method called population attributable risk. The method is used in human studies to determine how much a given disease could be reduced if certain risk factors were eliminated.
The study compared 285 owners who had given up their dogs with 748 who still had dogs. The results were published in the Aug. 1 issue of the Journal of the American Veterinary Medical Association.
The study did not look at strays brought to shelters, but only those dogs given up voluntarily by their owners. About half of the 4 million total dogs that end up in shelters each year are euthanized.
"Surprisingly, nearly half of the households that gave up a dog said they had planned the acquisition carefully," says Patronek, a veterinarian and former humane society director.
But only about one-fourth of the households that sought veterinary care said the doctor routinely offered advice on behavior or training.
"Visiting a veterinarian is a chance for the owner to learn what's normal and abnormal behavior and thus be more tolerant of the pet," Patronek says. "It's pretty clear from the study that increased education and outreach efforts by veterinarians, dog clubs and other animal-welfare groups could substantially reduce the number of dogs handled annually by shelters, of which about half are put to sleep."
However, because many dogs, especially puppies, are acquired free from friends and neighbors or through newspaper ads, it's more difficult to educate these owners about the responsibilities of caring for a pet, Patronek says.
"An even greater challenge is to reach new dog owners who don't initially seek veterinary care or dog-training services," he says. "Community intervention programs are needed to identify these owners and get them into the loop on formal training and veterinary care."
The research found that dogs obtained beyond puppyhood -- more than six months of age -- had the greatest chance of being given up for adoption. Also, a dog that was kept mainly in the back yard was about six times more likely to be given up for adoption than one kept in the house.
"It's the chicken or the egg thing," Patronek says. "These dogs might have come to the house behaving badly and were put in the back yard to be out of sight, out of mind. Or maybe they were nice dogs to begin with but the family never bonded with them because they were kept outside all the time."
The researchers also did a parallel study on common factors among owners who gave up their cats for adoption. Approximately 6 million cats (pets and strays) are brought to shelters each year, with about two-thirds being euthanized.
The researchers found:
About 36 percent of U.S. households have at least one dog, and about 30 percent have at least one cat, according to the American Veterinary Medical Association.
The study was funded by the Ralston Purina Co., two animal-welfare trust funds, and Purdue's Center for Applied Ethology and Human-Animal Interaction.
Other Purdue researchers were Dr. Lawrence T. Glickman, professor of veterinary epidemiology and environmental health; Professor Alan M. Beck, director, Center for Applied Ethology and Human-Animal Interaction; and George P. McCabe Jr., professor of statistics. Dr. Carol Ecker, a veterinarian and president of Clayview Animal Clinic Inc., South Bend, also assisted.
Source: Through Aug. 23, Gary Patronek can be reached at (765) 494-2294 and Internet,
patronek@vm.cc.purdue.edu On Sept. 1, he will join the Center for Animals and Public Policy at
Tufts University, phone (508) 839-7991.
Writer: Ellen Rantz, (765) 494-2073; home, (765) 497-0345; Internet, ellen_rantz@purdue.edu