Dogs may be "man's best friend," but parrots, cats, lizards and horses also form connections to human beings. Not only can having a pet cheer you up and reduce your stress levels, but your pet could save your life. These pets may be able to detect cancer, diabetic crises, seizures, migraines and Parkinson's "freezing," helping owners get timely -- and often critical -- help.
Dogs can actually be taught to detect cancer. Melanoma is the least common but most deadly skin cancer, accounting for 79 percent of skin cancer deaths. Diagnosis relies mostly on the way the skin looks -- even though many melanomas are invisible to the naked eye. But cancer causes the body to release chemicals into our urine, sweat and even breath that smells different than normal.
Tallahassee dermatologist Dr. Armand Cognetta heard about the terrific scenting prowess of dogs sniffing out bombs, termites and even dead bodies underwater and wondered if they might be able to detect skin cancer. As an experiment, he partnered with Duane Pickel, who specializes in training bomb detect dogs. George, the standard Schnauzer, was taught to detect cancer samples in test tubes -- and proved to be 99 percent accurate!
Once George knew what to look for, the team "planted" samples (both benign and cancerous) on human volunteers with Band-aids. Again, George was 100 percent accurate. Cognetta even convinced a few volunteers to let George sniff bare skin. And the dog found six melanomas that were undetectable by handheld microscope.
Carol Witcher's Boxer dog, Floyd Henry, was able to detect his owner's breast cancer, which was then confirmed as malignant by Dr. Sheryl Gabram-Mendola, a breast surgical oncologist at Winship Cancer Institute of Emory University. Both Witcher and Gabroam-Mendola agree that the dog saved her life. Dr. Gabram-Mendola has since developed a test that looks for different compounds in the breath of cancer patients.
Other programs in the UK and elsewhere use dogs to detect prostate cancer through urine samples. The British journal Gut reported that an 8-year-old Labrador named Marine, trained to detect colorectal cancer, was accurate 91 percent of the time when sniffing a patient's breath and 97 percent of the time when sniffing stool.
Seizure Assistance Dogs
Dogs can also be trained to respond to seizures, keeping owners safe by fetching help or medication. But we still don't know why dogs have the ability to pick up on a seizure before it occurs. It may be that they cue into subtle body signals, or even chemical changes that make our bodies smell different.
Early studies reported in both the January 1999 and January 2001 issues of Seizure magazine, posited that dogs trained to help people with seizures by bringing them medicine or alerting others to the situation, actually develop the ability to predict seizures and react in advance of an oncoming seizure. Some dogs learn how to do this by watching other dogs.
Migraine Alert Dogs
Migraines cause debilitating pain in 36 million people each year. And medications work best when taken as early as possible. Dogs, cats and other pets often naturally detect pre-migraine characteristics -- prodrome -- which may include irritability, yawning and dizziness, among others. There may also be subtle changes or smells that animals detect. Some dogs now have been trained to act as sentinels and warn owners to take medication far enough in advance to prevent the headache.
Diabetes Alert Dogs
Katie Jane Brashier, a high school student in Denison, TX was diagnosed with Type 1 diabetes four years ago. Her assistance dog, Shots, detects when her blood sugar level changes by sniffing her breath. The Labrador mix, adopted from the local shelter, received special training to help Katie Jane maintain a normal life and accompanies her to band practice, classes and doctor visits. Shots learned this skill by sniffing cotton balls scented with Katie Jane's saliva.
The British Medical Journal published a report written by Dr. Gareth Williams from Liverpool University Hospital, that discussed how pet dogs sensed an imminent hypoglycemic shock in their diabetic owners and warned them ahead of time to take proper medication. Even the Mayo Clinic has welcomed a diabetic service dog into the facility.
Pet dogs -- and even cats, rabbits and birds -- show behavioral changes when around people whose blood sugar level changes. Now some dogs have been trained to alert their owners to these changes. "Brittle" diabetics -- those with hard-to-control blood sugar levels -- may be fearful to leave home. Diabetic service dogs sniff their owner's breath and detect both high and low levels of blood sugar -- sometimes before it reaches dangerous levels -- allowing owners to lead more normal lives. Some of these dogs become so good at it, they "alert" random people around them and actually diagnose diabetes in people who didn't know that they had the condition. Dr. Debra Wells, of Queens University in Belfast, Northern Ireland, is currently analyzing data from a study to try and determine exactly where these powers of detection come from.
People suffering from Parkinson's disease can experience (among other things), a condition termed "freezing." Their feet suddenly stop moving while the rest of the body continues on, and the fear of falls can leave some people homebound. Service dogs are trained to tap owners on the foot, which often gets their partner moving again. In fact, some of these dogs learn to anticipate the freeze and stop it before it even starts.
Ultimately, experts don't know exactly how animals predict such things. While many animals may be able to detect and alert their owners to such changes, it takes a special bond for the pet to actually care and make it happen.
Amy D. Shojai, CABC, is a certified animal behavior consultant and the award-winning author of 23 pet care books. She also writes for puppies.about.com and cats.about.com and appears on Animal Planet's CATS-101 and DOGS-101. Check out Amy's latest book, Pet Care in the New Century: Cutting-Edge Medicine for Dogs & Cats on Red Room, where you can read her blog.