A landmark examination of what caused the deaths of tens of thousands of dogs over two decades is providing important new information that should help owners and veterinarians pinpoint potentially fatal disease faster and administer treatments that could save or prolong lives.
University of Georgia researchers Kate Creevy, with her border collie Makazi, and Daniel Promislow, with his dogs Frisbee and Silver, studied the causes of death in about 75,000 dogs.
Researchers at the University of Georgia investigated data to establish breed-specific causes of death in the 74,556 dogs that died while being treated at 27 veterinary hospitals in North America from 1984 to 2004.
The study, published in The Journal of Veterinary Internal Medicine, uncovered some surprises:
•Bernese mountain dogs, golden retrievers and boxers, long known to have extremely high incidence of cancer, were confirmed to die of that disease at high rates. However, the bouvier de Flandres, not previously generally regarded as a high-cancer breed, had the fourth-highest death rate from cancer; Scottish terriers had the third-highest.
•The five breeds with the highest relative proportion of death from gastrointestinal causes (including parvovirus and gastric dilation and volvulus syndrome — known as bloat) were Great Dane, Gordon setter, Akita, Shar-pei and Weimeraner.
•The breeds with the highest proportion of cardiovascular-related deaths were Newfoundland, Maltese, Chihuahua, Doberman pinscher and fox terrier.
Unexpectedly, Afghan hounds and Vizslas had a high relative proportion of death from respiratory disease.
"When we think of respiratory disease, we generally think of short, compressed noses," says veterinarian and project researcher Kate Creevy.
Respiratory disease was, in fact, the most frequent cause of death among flat-faced bulldogs.
But the rate of respiratory deaths in these two long-snout breeds was surprising (and as yet unexplained), and because most veterinarians don't see a sufficient number of either breed in their practices to detect a respiratory-disease pattern in them, exploring that as a possibility wouldn't be a natural first response to an ill dog, Creevy says.
Knowledge of breed-specific mortality patterns is often crucial to an accurate diagnosis and prompt, informed treatment, experts say. Though some ailments that often befall certain breeds are well known, such as disc disease in dachshunds, certain diseases are causing death in some breeds at rates far higher than has been widely known. Fox terriers, for example, are not usually associated with cardiovascular disease, but it was the leading cause of organ system death in that breed.
University of Georgia geneticist and project researcher Daniel Promislow says breeding for "certain characteristics" in some breeds has "inadvertently magnified" some of the predispositions for mortality patterns revealed in this research. And these findings can "help us think about the multiple effects" as well as serve as a step in unraveling more of the genetic secrets that will lead to healthier dogs that live longer.