Dogs depend on their noses, and so do we
By HELEN PALMER
This past week, I received the August issue of Dog Watch newsletter published by Cornell University College of Veterinary Medicine. There were two short articles on the scenting abilities of dogs.
In the past, I reported on dogs that were trained to locate buried land turtles, which are endangered, so they could be relocated in order for a new road that was planned for the turtles’ current habitat. My favorite report, back in the 1970s was from a video of three German shepherd dogs trained to locate moth egg masses. That species of moth was brought over by accident and was killing whole forests of trees.
I have also reported on dogs showing the ability to locate cancer in humans before the cancer tests registered any problem. After one dog demonstrated his ability, medical scientists were interested in trying to train other dogs to locate cancer. It seems that some dogs are able to learn, while others can’t seem to catch on.
The longest article, “Amazing Scenting Abilities,” by the newsletter staff stated that dogs are 10,000 to 100,000 times better than humans at detecting and identifying scents. It is estimated that dogs have about 300 million scent receptors in their noses.
They are capable of identifying the various components of a scent. That is why the drug sniffing dogs in airports can signal a package with drugs even though the drugs have been heavily wrapped in various smelly layers in an effort to fool the animals.
Dogs’ noses are not constructed like humans. The dog can keep inhaling and checking the scents while letting air escape through slits on the side of the nose. I trained my first standard schnauzer to track (which she felt was a dumb activity but would go along with me on one track a day). Since dogs can identify the location of a scent, she disqualified herself at a tracking clinic by taking a short-cut to the track going back to the starting point. The judge told me that the track was laid incorrectly and she would have a new track made and aged so my dog could compete. That was the first time I was aware that my dog could raise her head and identify the track 20 feet away going in the opposite direction.
The article also mentions the problems dogs have when they have a respiratory infection that interfere with scenting. Various medications can also disturb the dog’s ability to scent. This is important since the animal uses his nose to approve of his food. Often a sick dog will stop eating because he cannot smell his food. The writer suggests adding the juice from a can of tuna to try to stimulate the dog’s appetite.
The latest scent training involves detecting laurel-wilt-affected wood from avocado trees. This disease has already destroyed more than 300 million laurel trees in the United States, including the avocado tree. It is caused by the redbay ambrosia beetle, which came from Asia.