A canine's natural scenting ability is more easily adapted to the vegetative scent even though the vegetative scent is somewhat stronger at a given point. Given the proper training and a certain amount of time, a canine will virtually begin to discriminate on his own, thereby leading to more successful applications. A footprint in the grass with its corresponding vegetative scent is good to reassure your canine is on a track, but is not necessarily wise to encourage him to follow footprints exclusively. The reason being that you can never be sure that the person at the end of the footprint track is the same one that you started after several blocks back. Having explained vegetative scent, I feel obligated to explain a little further.
Most people feel that a good deal of scent which a canine follows comes from the feet.
This is not necessarily true. Secondly, the feet are enclosed tightly in shoes thereby trapping the rafts that do escape along with perspiration. One of the reasons a person's feet smell is because of the accumulation of the trapped rafts inside the shoes. Thirdly, there are no particular glands or cells in a person's feet which are more odorous that any other part of the body. About the only thing a canine may be following that is directly relative to a person's feet is the smell of leather, shoe polish, oil or some other material generally common to more than one individual.