How dogs that detect disease can help humans

How dogs that detect disease can help humans

For years, dogs have used their amazing sense of smell to help with tasks ranging from bomb detection to rescue operations. But some researchers now believe dogs may save human lives in a much bigger way – by detecting disease and other medical conditions way before we do. Let’s take a closer look at some of the work currently underway.

Dogs detecting cancer

Early detection can mean the difference between life and death when it comes to cancer so it’s no surprise that the number of dogs being trained to detect this disease is growing. Canines can sniff out a variety of cancers, including breast, skin, lung and bladder cancer. While scientists haven’t quite figured out the details, dogs appear to be able to pick up very low concentrations of the volatile organic compounds (VOCs) that malignant tumors generate. Trainers teach the dogs how to tell the difference between tissue, urine or breath samples from cancer patients and those of healthy people. When dogs detect cancer in a random sample, they are rewarded with a treat or favourite toy.

The firefighter’s masks are placed in bottles, loaded on a rack and slid underneath the holes. Here, cancer detection dog Buster finds a cancer sample.

While some groups are still in the research and training stages, others are actually “on the job”.

Quebec-based CancerDogs has been screening U.S. firefighters for lung cancer since 2011. They now work with 50 fire departments south of the border. Founder Glenn Ferguson says the dogs are more than 95% accurate at detecting cancer, and report less than 40% false positives. The experimental testing method is easy. After a firefighter breathes into a surgical mask for ten minutes, the mask is sent to staff at CancerDogs, who place it in a plastic vial. The dogs go to work from there, sniffing at the samples and raising a paw when they detect cancer. After that, a second sample is requested and, if it turns out positive, CancerDogs recommends setting up a doctor’s appointment.

Of course, anecdotal evidence of dogs detecting cancer in their humans is all over the internet. Back in 1989, a woman claimed her dog paid constant attention to a mole on her leg while ignoring others, and even tried to bite it off one at one point. Doctors excised the mole which did indeed turn out to be a malignant melanoma. Actress Shannen Doherty (90210) claims her dog, Bowie, sniffed obsessively at her upper right side prior to her breast cancer diagnosis in 2015.

Ultimately, researchers hope they will be able to reproduce the dogs’ ability to detect specific VOCs by using a device that detects the chemicals when a patient breathes into it. Right now, they’re hard at work trying to determine what those chemicals are.

Angus in training at Vancouver General Hospital.

Sniffing out C. difficile

It’s hard to talk about a hospital stay without the topic of C. difficile coming up. The Clostridium difficile (C. difficile) bacteria remains the most common cause of infectious diarrhea in hospitals and residential care facilities.

Now a Vancouver hospital is addressing the issue in an unconventional way – by bringing in C. difficile-detection dogs to inspect rooms. Former BC health minister and veterinarian Terry Lake recently awarded Springer Spaniel Angus his working dog badge, after he passed a probationary period that saw him discover the deadly bacteria on around 100 occasions since he started working at Vancouver General Hospital (VGF). The pilot program has been so successful that he is getting a working partner, another Springer Spaniel named Dodger.

The two dogs use their superior noses to sniff out even the tiniest pockets of the bacteria in fecal matter, which may remain even in cleaned rooms. Once they identify the superbug, the hospital staff brings an ultraviolet light disinfection robot that can eradicate 99.9% of C. difficile spores.

Lake said the program may some day expand to other hospitals. In the meantime, Angus’ work is helping to create awareness about hygiene and how to improve cleaning practices.

The idea for C. difficile detection dogs came from Angus and Dodger’s trainer, Teresa Zurberg, who almost lost her life to C. difficile. Zurberg is a former Canadian Force’s medic while Zurberg’s husband, Markus, is a nurse who works in patient safety and quality care at VGH.

MDD CEO and co-founder Claire Guest poses with a few canine members of the bio detection team. Jack (front) is a Parkinson’s detection dog.

Early warning for Parkinson’s

Scientists in the U.K. first got the idea to test out dogs for Parkinson’s after a Scottish woman with a highly acute sense of smell claimed she detected an odour change in her husband six years before doctors diagnosed him with the disease. Now, Manchester University and research charity Medical Detection Dogs are conducting a study funded by The Michael J. Fox Foundation for Parkinson’s Research and Parkinson’s UK, to determine if dogs can identify the VOCs associated with the condition. Since no test currently exists to definitively test for Parkinson’s and symptoms typically appear only after more than half the relevant nerve cells in the brain have been lost, this could help sufferers get treatment much earlier.

The trial will include two Labrador retrievers and a cocker spaniel who have been trained to sniff the skin swabs of 700 people in a double blind setting. The team will also split up the molecules to identify which key chemical indicator is involved in Parkinson’s.

Thanks to his Diabetes Alert Dog, Carson is able to live a fuller life.

Help for diabetics

For diabetics with sudden drops in blood sugar, fear becomes a way of life. Sufferers can slip unnoticed into a coma and never recover. Diabetic alert dogs are changing all that. These specially trained dogs use their sense of smell to detect hypoglycemic episodes, and alert their handlers so they can avoid loss of consciousness and the life-threatening effects that follow. By paying attention to the dog’s warning, diabetics can correct the fluctuation. Dogs are also trained to notify parents of children as young as eight years old with Type 1 diabetes if an episode is about to occur. They will go get help or activate an alert system.

There are several organizations in Canada training dogs for people with diabetes. One such organization, Sweet Charity Medical Assistance Dogs, based in Barrie, Ontario, was founded in 2013 by Lori Johnson, a teacher who also lives with Type 1 diabetes. Johnson had used therapy dogs in her classroom for years, and was inspired to do more after hearing Dr. Claire Guest, CEO and Medical Director of Medical Detection Dogs in the UK speak in Toronto.

Now the organization is helping kids like Carson, who was diagnosed with diabetes at age 3. Following his diagnosis, Carson required 24-hour monitoring. His parents became terrified that he would die during the night. When the Diabetes Clinic introduced Carson and his family to Xena, a Diabetes Alert Dog, they experienced immediate relief and gratitude. Today, this 2-year-old black lab goes everywhere with Carson, who is able to live a fuller life with his four-legged guardian by his side.

Minimizing the effects of seizures

For people with epilepsy, seizure alert dogs help decrease the side effects of a seizure. The dogs are typically trained to activate an emergency call system, alert a caretaker, retrieve medications or a telephone, stay close to help prevent injury, and stimulate a person to regain full consciousness. It’s an incredible emotional support for those who can lose complete control at any given time. But some canines actually learn to go way beyond their training, and intuitively know when a seizure is about to take place. Service dog trainers say they can’t predict which dogs will develop this skill but for those people fortunate enough to experience this additional assistance, it can make a world of difference.

Faye (not her real name) tells us that her Labrador Retriever can now predict a seizure several minutes before it happens. “He warned me so far in advance last time that I thought he had made a mistake,” explains Faye. “But then the seizure happened.” The warning gives her enough time to get to a safe place, on the ground, and call a friend who she has on speed dial to let her know what’s happening. Her dog remains with her throughout, ensuring she remains protected until she “wakes”.

Scientists don’t know whether these dogs are noticing a change in breath, heart rate VOCs or something else. Research is ongoing.