A new study is shedding more light on breed-specific causes of death in dogs. The findings can be used to create breed-specific health maintenance programs and is a starting point for future studies that will explore the genetic underpinnings of disease in dogs, according to the study’s researchers at University of Georgia.
The researchers examined data from the veterinary medical database to determine the cause of death for almost 75,000 dogs representing 82 breeds over the 20-year period of 1984 through 2004. They classified the deaths by organ system and disease process and further analyzed the data by breed, age and average body mass.
While some of the findings corroborate smaller, breed-specific studies, the UGA researchers said they also discovered new information.
For example, toy breeds, such as Chihuahuas and Maltese, are known to have high rates of cardiovascular disease (19 percent and 21 percent of deaths within the breeds, respectively), but the researchers found that Fox Terriers also have high rates of cardiovascular disease accounting for 16 percent of deaths.
Another example: Golden retrievers and boxers are known to have high rates of cancer (50 percent and 44 percent of deaths, respectively), but the researchers found that the Bouvier des Flandres, a relatively rare breed, also has a high death rate from cancer at 47 percent.
The previously unknown high risk of cancer in the Bouvier highlights the power of the study’s comprehensive approach, said study co-author Kate Creevy, DVM, an assistant professor in the UGA College of Veterinary Medicine.
“With rare breeds, an individual veterinarian may not see enough cases to be able to develop the opinion on whether the breed has a high incidence of conditions such as cancer,” Dr. Creevy said. “But if you analyze records that have been compiled over 20 years, you can detect patterns that you wouldn’t otherwise notice.”
The study may also help solve one the great enigmas of canine health, according to study co-author Daniel Promislow, Ph.D., a genetics professor in the UGA Franklin College of Arts and Sciences.
“Normally, if you compare different species of mammals, big ones live longer than little ones—elephants live longer than mice, and sheep are in the middle, for example—and that pattern holds pretty well across hundreds of different species of mammals,” Dr. Promislow said. “Within dogs, the opposite occurs; the little dogs live longer.”
The researchers found that larger breeds are more likely to die of musculoskeletal disease, gastrointestinal disease and cancer. Smaller breeds had higher death rates from metabolic diseases, such as diabetes and Cushing’s disease.
Overall, dogs are an ideal species in which to explore the genetic basis of disease, according to Promislow. There’s an unparalleled degree of diversity among breeds yet all dogs are of the species Canis lupus familiaris. Within breeds, on the other hand, dogs are genetically very similar, he said.
In addition, understanding the genetic basis of disease in dogs can benefit human medicine. This is because the building blocks of the dog genome and the human genome are the same, Promislow said.
The study is published in the March/April edition of the Journal of Veterinary Internal Medicine.