Genetic Variation in Scenting Ability

Natural detection task is very revealing
By Karen B. London PhD, June 2016

We all know that Beagles have better noses than Whippets, right? This almost seems too obvious to point out, especially to anyone who has ever had a dog of either breed. However, the authors of a recent study claim to be the first to scientifically document a difference in olfactory abilities across groups of dogs.

The researchers compared scenting ability across four groups of canines: dog breeds that have been selected for scenting abilities, dog breeds that have not been selected for scenting abilities, short-nosed dogs and hand-reared wolves. The task asked of these animals was simple—find the raw meat in a container that is hidden underneath one of five pots. There were multiple tests that varied in difficulty based on the number of holes in the container’s lid.

The results of the study were that dogs bred for scenting ability performed better than both short-nosed dogs and dogs who were not bred for their olfactory capabilities. The short-nosed dogs performed worse than any other group, suggesting that breeding for this head and face shape has adversely affected olfaction. In the most difficult of the tests, only wolves and the dogs bred for scenting abilities performed better than what would be expected if the animals were just guessing. Wolves improved their performance when they were re-tested, but the dogs in all three groups were no better the second time around.

Since dogs did not improve with repeated testing, this test may be a useful one-and-done way to assess a dog’s scenting capabilities. That is important because there is currently no standard method for testing the olfactory ability of dogs, but the method in this study could be used for quick assessments of dogs’ abilities. Most ways of testing dogs involve a match-to-sample design, which means that the dogs are taught a scent and they then have to find the same scent from among a group of scents. That requires extensive training, so it is impossible to determine to what degree those tests are assessing trainability and to what extent they measure scenting ability. Both trainability and olfactory ability are important for success as a working detection dog, but there’s great value in evaluating each trait independently.

Karen B. London, PhD, is a Certified Applied Animal Behaviorist and Certified Professional Dog Trainer who specializes in working with dogs with serious behavioral problems, including aggression. She is the author of five books on canine training and behavior.