Dog as a diagnostic co-pilot

It’s no secret that dogs can identify several types of cancers, including prostrate, breast, colon, and lung

Cancer-sniffing dogs are helping researchers develop an early-detection blood test for ovarian cancer.

It’s no secret that dogs, through the wonders of their noses, can identify several types of cancers, including prostrate, breast, colon, lung, thyroid and ovarian cancers, and melanoma. However, as fascinating as this ability is, it’s unlikely dogs will be ‘working’ side by side in-clinic with general practitioners and oncologists any time soon.

So why, then, does it matter whether dogs can sniff cancer? What’s the practical application?

The future possibilities are significant, according to Cynthia Otto, DVM, PhD, executive director of the Penn Vet Working Dog Center; associate professor of critical care at University of Pennsylvania School of Veterinary Medicine; and researcher into the impact of 9/11 on search-and-rescue dogs.

Dr. Otto and her group, working in collaboration with Monell Chemical Senses Center, Penn Physics, and Penn Medicine, are close to identifying the specific chemicals dogs are targeting when they ‘smell’ ovarian cancer, which could result in an early-detection blood test, she says.

Unfortunately, by the time ovarian cancer is diagnosed, aggressive treatment is required—too often without success.

“If a simple blood test could offer a very early diagnosis, many lives would be saved,” says Vallie Szymanski, co-founder and executive director of Ovarian Cancer Symptom Awareness (OCSA), a St. Charles, Ill.-based non-profit that helps fund Otto’s work. One OCSA fund is named for Darlene Arden, an award-winning pet author and certified animal behaviour consultant who succumbed to ovarian cancer in 2017.

One of several project collaborators is an oncological surgeon who provides the blood samples. The dogs sniff the samples of patients with ovarian cancer and are ‘clicked’ (with a dog training clicker), and promptly rewarded with praise and a treat. Eventually, a normal blood sample is added to the mix, but the dogs are rewarded only when identifying the cancer sample. Finally, a sample is added from a woman with an ovarian-related medical issue, such as a cyst (benign ovarian disease). Dogs quickly learn to distinguish between this ‘false alarm’ and true cancer.

The dogs take about two weeks to begin to catch on, and after a few months of training, they get it right at least 85 to 90 per cent of the time, Otto says.

“This is clearly statistically significant,” she adds. “There are three choices for the dogs, and only one is right. It’s mind-boggling as to how dogs can do this so often. I am amazed at the possibilities.”

How does the nose know?

Otto has partnered with chemists and physicists who are attempting to determine exactly what chemical changes occur in ovarian cancer patients. The physicists essentially are attempting to recreate a canine nose to find out what dogs are catching when they detect cancer.

Otto is confident that as long as she and her team receive ample financial support, she’s three to five years away from developing a blood test that essentially will translate what dogs are telling researchers. Unfortunately, most ovarian cancer groups aren’t interested in funding her work. “They don’t get it,” she says.

Another OCSA co-founder, Susan Roman, was one of the driving forces behind the organization.

“[Susan’s] dog Bacchus was so persistently sniffing at her,” Szymanski says. “She saw her doctor based on her dog’s insistence. She just thought her dog was trying to tell her something.” She was right.

“Susan had no symptoms, but the diagnosis was ovarian cancer,” Szymanski explains.

Sadly, despite Susan’s dog’s actions—and reasonably early warning—it wasn’t early enough, but from her diagnosis, OCSA and its promise became reality.

Why this industry?

“I know how much our clients share with us,” says Kurt Kleptisch, DVM, of St. Charles, Ill., who serves on the OCSA board. “Veterinarians know it’s not unusual for clients to share their own health concerns with us. I point out I am ‘not that kind of doctor.’ But based on the trust clients have in me, they share. By making veterinarians aware of ovarian cancer symptoms and encouraging clients to see their doctors, we’ve helped a lot of people.”

“We’ve always known dogs can play a role,” Szymanski says. “That feeling was based on Bacchus’s actions. But we didn’t know how vital that role might be until we were introduced to Darlene Arden, and then Dr. Otto.”

Arden once told me, “A dog’s nose is God’s greatest miracle. It’s no coincidence dog is god spelled backward. Eventually, researchers on the human side may find a drug or treatment for ovarian cancer. Too many women can’t wait for that to happen. Veterinary-funded studies get things done!”

If indeed the funding comes through, and progress continues, a blood test for ovarian cancer will happen, Otto says, adding that once the recipe is set, it will be reasonably easy to duplicate the effort for other types of cancers, as well.

When given that news shortly before her death, Arden said, “Thank dog!”

Steve Dale is a certified animal behaviour consultant who speaks at animal welfare and veterinary conferences. Visit his website at Columnists’ opinions do not necessarily reflect those of Veterinary Practice News Canada.

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