At Cambridge University Veterinary School in England, researchers are awaiting funding to begin testing the viability of what they call “dognoseis” – the theory that dogs can be trained to detect prostate cancer by smelling traces of the disease in urine samples. Although many medical professionals remain skeptical, the veterinary researchers hope that dogs might someday play a role in screening patients for prostate cancer.

There is anecdotal evidence suggesting that dogs can detect changes in the smell of a cancerous growth. A Doberman-border collie mix belonging to a British woman constantly sniffed at a mole on her thigh and once even tried to bite it off. She decided to have it checked and it turned out to be melanoma. According to her doctors, the dog may have saved her life by causing her to seek medical advice while the mole was still at a thin stage.

In another case, a pet Labrador retriever repeatedly pushed his nose against his owner’s leg, sniffing a lesion through the man’s pants. The owner had the lesion checked and it was found to be basal cell carcinoma, a form of skin cancer, and was removed. Neither dog showed any interest in the owner’s lesions after they were removed.

In Tallahassee, a dermatologist collaborated with a police dog handler to train dogs to locate and identify tissue samples of melanoma that had been removed and stored. When the dog became 100% successful in detecting melanoma samples, the doctor had him smell suspected areas on his patients. The dog was nearly 100% successful in detecting cancerous skin lesions.

Researchers don’t know exactly what dogs will smell in the urine of prostate cancer patients, but they feel confident that they will find some unique scent and can be trained to respond to it. After all, they are born with one of nature’s finest smelling tools.

Dogs and humans both smell odors using a membrane called the olfactory epithelium. This membrane is lined with receptors that are topped with tiny hairs that pick up chemicals and transmit the sense of odor by sending electrical signals to the brain. Humans have about 40 million olfactory receptors while dogs have about 2 billion, giving dogs a sense of smell that is thought to be at least a thousand times sharper than ours.

Whether any of this research will ever result in dogs being used as a medical diagnostic tool is questionable. Even if the dogs could achieve a 100% accuracy rate, it is unlikely that many health care providers will pay for a dog’s opinion, let alone authorize expensive and intrusive follow-up procedures based on that opinion. Only time will tell.