(CNN) -- Dogs are using their noses to sniff out cancer in humans.
Doctors usually rely on sight, sound and touch when diagnosing certain diseases.
Yet they rarely use the sense of smell, even though many diseases do have their own distinct chemical makeup, but is not obvious to the human nose.
Now with special training, dogs are being used to develop new diagnostic tests for certain illnesses by using their keen sense of smell.
what kind of diseases are they sniffing out?
Half researcher, half detective, this pup possesses an investigative tool that even sam spade would envy.
Like most dogs, the springer spaniel is equipped with an acute sense of smell that can detect chemicals and changes in odors that humans and technology cannot.
"The great thing about dogs is not only are they more sensitive but they can filter things out."
In this case, McBaine and other dogs at the Penn
Why this particular cancer?
Scientists know that early ovarian cancer cells have special odors that can't be identified by standard methods, because they intertwine with other odors in the tissues.
But a dog can recognize and weed out the cancer odor easily, much like McBaine is doing here.
"We switch the sample location we change things around just to make sure that we are very confident that that's what detecting."
By using the dog's sense of smell, researchers hope to narrow down a specific odor so scientists can design a blood or urine test that can detect ovarian cancer in its earliest stages.
"We are trying to use the dogs to perfect the chemistry."
Something McBaine and his four-legged buddies are more than happy to do.