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Canine Behavior Specialist Trains For Cancer Detection
Dogs pix
Karma, a specially trained black lab, displays her ability to sniff out cancer from patient samples in one of five cups on the floor at a recent demonstration at Spring Creek Country Club. Photo By Glenn Kahl

California Canine Co. owner Dierdra McElroy demonstrated the use of her cancer detecting dogs recently for a Rotary presentation at Spring Creek Country Club – reporting 375 positive peer review studies over the past five years.

McElroy, who provides the ‘Didi’s Dogs’ column on a regular basis for The Times, is from Lathrop. She brought a black lab, Karma, into the meeting room at Spring Creek where the dog showed its proficiency at locating the one hole that would normally contain urine from a suspected cancer patient and hit on the correct hole that in tests confirms the presence of a malignant tumor below stage one of its growth.

McElroy now has a team of five certified cancer sniffing canines, and also brought a lovable English Bulldog “Zeus” to the meeting, acknowledging that because of his short snout, it takes him 30 times longer than a Labrador to hit on a cancer in a study.

“What we are looking for are dogs with a ‘hunt drive’ and I can train Dutch Shepherds (to be proficient) in just six weeks. Our goal as a group of trainers is to get public screening approved within five years,” she said.

For demonstration purposes, McElroy placed a small amount of food in one of the cups (instead of urine) to show the dog’s reaction in finding its target out of five choices. She said the dogs can tell the difference between malignant and benign tumors just by sniffing out the cups. They can also pick the cancerous urine over multiple diseases. Duke University and UC Davis have both undertaken studies and St. Joseph’s Hospital in Stockton has offered her an office space in their facility for a colorectal study, she said.

McElroy said she declined because she would lose control of her study to the hospital.

“It is important during training for our bio-dogs to learn to check each and every scent hole and then ‘alert’ on only the holes that have the target odor of the cancer. An alert has the dog putting its nose in the correct hole and sitting down simultaneously,” she said.

McElroy explained that in cases of some ovarian, prostate and pancreatic cancers the medical community is often unable to detect a tumor until it reaches later stages, where her canines have proved detection below stage one.

She explained that some 40 percent of men and women will be diagnosed with cancer at some point in their lives.

McElroy said her firm, California Canine, has been doing crime analysis for years in searching out illegal drugs before she got into the cancer studies. Some 300 urine samples are needed to train a dog, she explained. It takes some six months to run a study, she added.

Asked if she could tell someone on the street or in an elevator why her dog was nuzzling them, she responded that it would be ethically immoral because the federal government had not approved the concept or the process.

Her current team of cancer detection dogs includes names like Karma, Louis, Olivia, Zeus and Felony with each dog cross trained to detect different forms of cancer.

She explained the abilities of a dog’s nose: Is having a unique print to each dog like our fingerprints; has 300 million scent receptors compared to our five million; the brain area that processes scent is 40 times larger in dogs than humans.

Dogs have an organ other animals do not have that is used for scent discrimination – Jacobson’s Organ – and can smell in parts per trillion which is equivalent to one drop of water diluted in 20 Olympic sized swimming pools.

McElroy said there are hundreds of peer review clinical trials proving that dogs are 99 percent accurate at sniffing out cancer and credited her own family pet with helping her discover her own case of cancer; which was found with a follow up biopsy and then removed.

For more information go to or or Cancer Sniffing Dogs of California on Facebook or by calling (209) 679-2033.