how strong is a dog's sense of smell?

Beagle sniffing flowers | How strong is a dog's sense of smell?
Posted by Dr. Kim Smyth on Aug 27 2013

It might be obvious that dogs can smell much better than we can, but just how much better is rather astounding. A dog’s sense of smell is in the order of 10,000 to 100,000 times better than ours, which is a number that can be hard to imagine. It’s because dogs can detect odors in parts per trillion that they can smell scents on a trail that are a week old. Imagine your dog going for a walk and being able to smell everyone who had been there for the past week – no wonder he stops to sniff so often!

Why do dogs have such a strong sense of smell?

The reason that a dog’s sense of smell is so much better than ours is twofold.

First, they have more olfactory receptors than we do. While a dog’s muzzle looks relatively uncomplicated, in fact, inside it is the complete opposite. Just behind the nostrils, the dog’s nasal cavity turns into a haven for scent, with layers of scrolling cartilage lined with olfactory cells. Dogs have an estimated 300 million olfactory cells, compared to our measly 10 million.

Secondly, the area of the brain dedicated to processing scents is bigger than ours. While our brains are larger than a dog’s brain, the scent area in dog’s brains is a whopping 40 times bigger than ours relatively! Both of these differences combine to allow our canine companions to smell things we can’t even begin to imagine.

Scent work for dogs

Consider dogs who work search and rescue missions. These dogs track the scent of a missing person through all kinds of terrain. They keep their nose to the grindstone, so to speak, and follow their target’s scent on a path that is riddled with thousands of other smells as well.

The keen noses of our dogs also keep them employed in many other scent related jobs, from searching for illegal drugs and explosives to the morose job of looking for cadavers. A dog’s sense of smell is so powerful that it can detect cadavers in 80 feet of water! More recently, dogs have been used in some studies to detect cancer cells – just another one of the potentially lifesaving ways dogs help their human counter parts.

You don’t have to have a professional tracking dog to experience the power of the canine nose. The American Kennel Club hosts tracking competitions, with elaborate tracks laid out for your pet to follow. You can start by volunteering at these events to see what goes on and learn the ropes. Participants will be able to give you tips and tricks of the trade to turn your dog into a super star sniffer!

Training your dog for tracking events utilizes his natural abilities and enriches the bond the two of you share. Tracking is hard work for both owner and dog, engaging both your dog’s mind and allowing him to exercise as well. At the end of the day, you’ll have a thoroughly exhausted (and extremely happy!) scent hound!