Thanks all for your comments. Here's what one person said and I found posted on the web - . . .
"Dog paws contain scent glands. There are also glands in between the toes. The action of scraping the paws against the ground helps release the scent inside of the glands. Dogs scrape the ground in order to increase their scent on the area near the feces pile, according to veterinarian Dr. Justine Lee. Before domestication, dogs wandered in large territories. One vital way to communicate with other wandering dogs is through scent marking. This instinct has not been bred out of the domestic dog." bb
