Excessive bleeding disorder in sighthounds predicted via genetic test

A potentially deadly disorder that causes excessive bleeding and bruising in canines following surgical procedures may soon be stopped before it starts, thanks to a new discovery.

Veterinary researchers at Washington State University (WSU), with support from the Scottish Deerhound Club of America, have developed a genetic test to help in predicting delayed postoperative hemorrhage (DEPOH), an excessive bleeding condition primarily observed in sighthounds.

DEPOH typically occurs one to four days after major surgery when blood clots begin to break down too soon in a process called hyperfibrinolysis. The severity can range from minor bruising to life-threatening hemorrhaging, WSU reports.

“Clotting factors stop the bleeding when you’ve had surgery, but you don’t want that blood clot to hang around forever,” says the study’s corresponding author, Michael Court, BVSc, PhD, DACVAA. “Normally, the body breaks down that clot as the tissue heals—usually over days to weeks; not just one or two days, as it does in dogs with the mutant gene.”

First recorded in greyhounds, delayed postoperative hemorrhage has since been noted in other sighthound breeds, including Scottish deerhounds and Irish wolfhounds, WSU reports.

To pinpoint its genetic cause, researchers evaluated 269 Scottish deerhounds and used genome-wide association analysis to identify a single region on chromosome 9 that contained 40 candidate genes. Further screening of the candidate genes was then performed, and only the DEPOH gene was identified as being directly linked to the pathophysiology of the condition.

After identifying the gene, researchers, including Holly Neibergs, PhD, a professor in WSU’s College of Agricultural, Human, and Natural Resource Sciences, examined samples from WSU’s pet DNA bank and discovered the mutation in additional sighthounds, including Italian greyhounds and salukis, as well as in other popular breeds, such as golden retrievers and border collies.

While DEPOH can be prevented by administering drugs prior to surgery, indiscriminate treatment can be costly and lead to adverse reactions to the medications, WSU reports. The newly available test, known as DEPOHGEN, will make it possible for veterinarians to detect the gene in pets prior to non-emergency surgeries and give preventative treatment when warranted.

Dr. Court, who is a professor of pharmacology and genomics in WSU’s College of Veterinary Medicine and Program in Individualized Medicine, hopes the test will eventually be included in common health panels used to evaluate puppies and dogs for a variety of conditions.

“Dogs with the DEPOH mutation have a much higher risk than other dogs of developing this after undergoing surgery,” he says. “[This new] test will allow us to prevent delayed postoperative hemorrhage by administering antifibrinolytic drugs to dogs that test positive for the gene before any surgery.”

A patent application has been submitted on the test by WSU with Court, the Scottish Deerhound Club of America, and the club’s health and genetics commission chair, John Dillberger, DVM, listed as coinventors.

“Now pet owners can test their dog at any time in its life to understand whether it is at risk,” Dr. Dillberger says. “If it is, before planning any scheduled or elective surgery, they can make sure the surgeon is aware of it and prepare accordingly. This will help save the lives of pets.”

The study has been published in the Journal of Veterinary Internal Medicine. To access it, click here.