RESEARCH - Canine Genetic Study Can Help Breed Healthier Dogs & Fight Disease in People

Domestic dogs share hundreds of diseases with humans and ground-breaking research out of Cornell University relying on canines might lead to discoveries in fighting disease in people.

The largest genetic study of dogs conducted by the university, recently published in the journal Nature Communications, saw the genetic analysis of 4,200 dogs.

And the findings are a coup considered it could offer a viable lead to help link genetic markers of disease with the responsible gene.

“The more we know about the genetic basis of diseases, the better we are at keeping pure-bred dog populations genetically healthy,” says Adam Boyko, assistant professor of biomedical sciences at Cornell’s College of Veterinary Medicine and the paper’s senior author.

The study investigated 180,000 genetic markers, DNA sequences with a known physical location on a chromosome – ultimately offering “a big step toward efficiently mapping genes responsible for complex disease in dogs, most of which are very similar in humans, thereby accelerating our understanding of human genetic diseases.”

Researchers say that by identifying important genes and proteins in dogs for diseases and traits, it may be possible to then test those homologous genes in humans.

In the study, samples were taken from more than 150 purebreds, 170 mixed-breed dogs and 350 free-ranging village dogs from the Cornell Veterinary Biobank with the work taking place over several years.

From hip dysplasia to lymphoma, dogs share more than 350 diseases with humans and similar pathways and genes associated – making mutts increasingly popular as model subjects for studying human disease.

As well genetics in dogs are far more simple than in humans making relying on them as research tools a “useful and underused way to understand genetic diseases from a human perspective,” Boyko says.

Existing research has made links between standard poodles and squamous cell carcinoma, German shepherds at atopic dermatitis and canine compulsive disorder in Dobermans, the study cites, while stating “domestic dogs” are “excellent animal models for human disease.”

In the Cornell study, for instance, hundreds of genes contribute to body size in humans while the research proved much easier with canine subjects.

“We found 17 genes for body size in dogs, and by looking at those genes we can predict a dog's size with 90 percent accuracy,” Boyko says.

For complex diseases, researchers identified areas on the genome associated with elbow dysplasia, hip dysplasia, lymphoma, mast cell tumour, granulomatous colitis and idiopathic epilepsy, which is often described as epilepsy without cause and often used to describe genetic epilepsy.

In addition to body size, researchers also succeeded in identifying genes which influence traits like fur length and shedding.

Human disease-mapping studies generally include genotyping tens of thousands of individuals and looking at 1 million markers across the genome.

In this study, Boyko says, researchers conducted simulations to show that “in dogs, we expect to be able to identify genetic risk factors for most major diseases with 1000 individual dogs and 1000 controls.”

The study was funded by Zoetis Animal Health, the Cornell University Center for Advanced Technology in Life Science Enterprise, the National Geographic Society, National Institutes of Health, The American Kennel Club and the Cornell University College of Veterinary Medicine.

By Nadia Moharib

Nadia Moharib is an animal lover who has adopted everything from birds to hamsters, salamanders, rabbits, fish and felines. She has written about all-things-pets for years and was a long-time editor of a pet magazine in a daily newspaper which featured a Q & A column, Ask Whit, penned by her pooch (ghost written, of course.) The serial dog owner lives in Calgary, Alberta and most days can be found at a dog park picking up after her rescue pooch, Scoots.