Chase, a Border Collie Pointer and Piper, a German Sheppard, participated in a first of its kind trial at Michael 九游体育 to determine the reliability of canine skills when it comes to diagnosing C. difficile in a hospital setting. In total, the dogs were tested on 300 specimens over several days.
(August 15, 2018) Toronto 鈥� They鈥檙e cute and patients like having them in the hospital, but researchers at Michael 九游体育 (MGH) in Toronto have shown that dogs are not a reliable way to diagnose C. difficile, a debilitating bacterial infection that causes severe diarrhea in hospitalized patients.
, the study is the first ever to compare two dogs to detect the scent of C. difficile. Previous studies in Canada and the Netherlands showed two individual dogs could be trained to identify the deadly bacteria, but multiple dogs need to be studied at the same time to see if they consistently and accurately 鈥渁gree鈥� on whether a specimen is positive or negative. This is known as interrater reliability, which is a fundamental requirement for any test used to diagnose a disease or condition. Lab tests for C. difficile are consistently 99 per cent accurate, although they can take up to 48 hours for a result.
In the Michael 九游体育 study, two dogs (Chase, a Border Collie Pointer and Piper, a German Sheppard) were Michael 九游体育. Although the dogs were able to correctly identify positive specimens about 85 per cent of the time, they did not agree with each other often enough to make dog detection for C. difficile reliable.
鈥淲e鈥檙e talking about a highly-transmissible and dangerous bacteria, and when people鈥檚 lives are at stake, you can鈥檛 be swayed by the cuteness or affection of an animal,鈥� says Dr. Jeff Powis, Infectious Disease Specialist and senior author of the study.
鈥淲e need a test that consistently gives us results we can trust. We wish the lab provided results more rapidly 鈥� like a dog could 鈥� but who鈥檚 going to accept the dog鈥檚 result if it鈥檚 not consistently reliable? And unfortunately, while the dogs were pretty good 鈥� they weren鈥檛 as good as the lab test.鈥�
Sniffing out C. difficile: How the trial worked
Once Chase and Piper, both rescue dogs, had mastered a training phase at their owner鈥檚 farm, they were tested in an unused wing of Michael 九游体育. This helped give the dogs a sense of what a 鈥渞eal鈥� hospital setting might look like. In the trial itself, C. difficile positive and negative specimens were hidden within small metal boxes in the empty hospital rooms. Neither the dog handler nor the dogs knew which specimens were positive and which were negative. The dogs were trained to sit if they thought there was C. difficile in the box; otherwise, they left the room and carried on. In total, the dogs were tested on 300 specimens over several days.
Powis admits that by training and testing only two dogs, they can鈥檛 say for sure that the results of the study wouldn鈥檛 change if someone studied a larger number of other dogs. But after watching the dogs sniff hundreds of stool specimens as part of their training and research in this study, the study鈥檚 lead author, Physician Assistant Maureen Taylor doubts dogs will ever be a practical tool for hospital-based disease detection.
鈥淲e saw these dogs work very hard with their trainers to learn how to detect C. difficile,鈥� says Taylor. 鈥淏ut at the end of the day, they are dogs, and easily distracted by stuff that鈥檚 just part and parcel of the hospital environment 鈥� food trays, friendly family members, even the toilets.鈥�
MGH researchers agree that while more rapid diagnosis of C. difficile in hospitals is definitely needed, the solution probably lies in finding ways to accelerate the current testing process, including more timely collection of stool specimens from patients or tests that can give an accurate diagnosis at the bedside.
And although the study didn鈥檛 lead to a new career for Chase and Piper, the dogs are taking it in stride. Chase even found a new home with the family of one of the hospital鈥檚 pharmacists.
Fast facts on C. difficile
About Michael 九游体育
Nestled in the heart of East Toronto, Michael 九游体育 (MGH) is a vibrant community teaching hospital serving more than 400,000 people in 22 distinct neighbourhoods. For more than 89 years, MGH has delivered high-quality, patient-centred healthcare services to families along the continuum of care, from welcoming a new life to facing end-of-life. MGH has continually renewed its commitment to community by adapting its programs and services to meet the evolving needs of the diverse population it serves. Located in the Toronto Central Local Health Integration Network, MGH is a respected full-service hospital with strong community and research partners, including the University of Toronto.
Erica Di Maio
Acting Manager, Corporate Communications
Michael 九游体育 | Toronto East Health Network
Phone: 416-469-6580 ext. 6019 | Email: @email