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Lee Fausett

Lee Fausett

A dog’s sense of smell is its most developed sense. Dogs are able to smell better than they see and even better than they can hear. The ability varies between dog breeds based on the length of their nose. The increased ability to detect but discriminate between many different odors is being utilized in increasingly diverse ways.

Dogs increased ability to smell is derived mainly in two main ways. The first is that dogs have many more scent detecting receptors than humans. The average human has 5 million receptor cells. A Dachshund may have up to 125 million, a Beagle or German shepherd 225 million and a Bloodhound up to 300 million receptors.

Dogs also devote more of their brain to processing smells. They utilize about 40 times more brain area than humans. With this combination, it is estimated that dogs can smell up to 100,000 times better than people can. Hunting, tracking, search and rescue, explosives and drug-detecting dogs are familiar to most people. 

Canine anesthesia assistant

Recently a service dog was permitted to assist monitoring a patient during a surgical procedure in a hospital. Kaelyn is a young girl who has the rare condition of mastocytosis. Because of this, she can suddenly and easily go into a life-threatening allergic type reaction. JJ, her trained assistant dog, has the ability to detect and alert someone very early to the start of a reaction. This early detection has permitted Kaelyn to have a more normal life. 

Last month she was in need of a surgical procedure. At Duke University Medical Center, the attending surgeon and anesthesiologist utilized JJ and her trainer in the surgery room to help them monitor Kaelyn. In a previous hospital situation, JJ alerted staff to a reaction about four minutes before any other monitoring equipment alerted them to a reaction. 

Service dogs have also been trained and utilized to detect changes in a diabetic person’s blood sugar levels. They can alert their diabetic owner of an arising situation in time so corrective action may be taken.

Other scent discrimination dogs have been trained for early detection of ovarian, bladder and prostate cancer. About 80 percent of ovarian cancers are detected after they have passed the curable stage. Trained dogs have been very accurate in early detection. While it is not yet routine to have a scent dog as part of a human physical exam, more research, experience and time may lead to this becoming more routine.

Scent discrimination dogs are also utilized for such diverse things as peanut detectors for those with peanut allergies. Border and custom control use dogs detecting narcotics, money, food, fruit, meats and other illegal contraband. Jails and prisons use dogs to detect contraband being smuggled in such items as tobacco, cellphones, drugs and other items.

Only a small percentage of dogs have the ability to become a highly skilled and trained scent detection dog. Only one in 70 dogs tested in one study had the ability and could be trained professionally. The typical dog obedience trainer does not have the experience or expertise for this type of training. Even rarer is a pet owner able to identify and train their own pet to become a scent detector dog.

If someone is interested in obtaining a scent dog, they need to contact a reputable professional trainer.

Dr. Lee Fausett is a longtime Hanford veterinarian. Contact him at with questions about this column.

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