Shelters are often noisy, hectic and scary places for most of the 3.3 million dogs that enter them each year in the United States. Concern about the well-being of shelter dogs prompted a number of scientific studies, which conclude that offering dogs an opportunity to use their noses eases stress, reduces excessive barking and improves sleep.

In my role as a behavior consultant and certified nose work instructor for Marin Humane, I’ve witnessed the extraordinary impact a simple sniffing session can have on a highly stressed, overwhelmed or under-stimulated dog. After just one round of sniffing out the treat from a box, you can see dogs that are shy, shut down, nervous and mouthy begin to relax. Dogs possess up to 300 million olfactory receptors in their noses, compared to about 6 million in us. And the part of a dog’s brain that is devoted to analyzing smells is, proportionally speaking, 40 times greater than ours. Scenting is a rewarding outlet for stress and boredom and a great mental workout!

Marin Humane is lucky to have dedicated volunteers who run a wildly successful program known as Shelter Scents, a version of K9 nose work for shelter dogs. Twice a week, the husband-and-wife team of Burt Greenspan and Donna Kalal lay out various boxes and containers for a K9 nose work search while other volunteers gather up adoption dogs and wait in line for their turn. In a six-month period last year, they offered 43 classes for a total of 108 dogs attending 249 times. Several of these dogs were adopted by onlookers who stopped in to watch the fun.

After every session, Greenspan and Kalal send a recap to their fellow volunteers, highlighting the individual dogs in a unique and humorous style. They also post video of the dogs on a dedicated Facebook page, and share them through the volunteer group website.

But scenting for shelter dogs is not all fun and games. K9 nose work is now a go-to behavior modification for dogs like Duck and Luna.

Duck, a gorgeous adolescent white German shepherd, arrived at Marin Humane with some disturbing spinning behavior. He could not stand still and constantly chased his tail, spinning every four seconds or so. After one scenting session the spinning began to lessen. After a week or so of short scenting sessions, the spinning had completely disappeared. Duck was recently adopted.

Luna, a young Siberian husky mix, was lovely to look at but difficult to handle given her jumping and nipping behavior. Participating in Shelter Scents classes provided a much-needed opportunity for her to relax and focus on finding the treat in the box. Luna has since been adopted as well.

Need more information on the benefits of K9 nose work? Visit a Shelter Scents class at 3 p.m. Fridays or Sundays in either the auditorium or pavilion at Marin Humane. Or, audit a nose work class. Go to for further details.