Basics of Scent Science

Anybody that has spent anytime with a dog knows that they use their noses to explore the world around them. Olfaction delivers the greatest amount of input for your dog and he will navigate the world by using his nose before any other senses. A dogs hearing is the second most important sense and their sight is the the third most important. For our versatile dogs, scent will be a big part of how they find game I will give a quick rundown on scent science. Most of the research done in this field has been done in the Search and Rescue dog sports, but the more we understand from this the better we will be at putting our dogs on birds and trails.

The average number of of human olfactory cells is about 5 million. The average number of olfactory cells in a German Shepherd is about 220 million cells. The average number of olfactory cells in a Labrador Retriever is over 300 million cells. The olfactory bulb of the dog is more than 1/3, 35%, of his total brain while for humans it is only about 5% of the brain. The way dogs smell is very different than how we as humans smell. When we walk into a room and smell a bowl of chili, we know what that smell is because of the combination of ingredients. Dogs, on the other hand, can break down that combination of ingredients and smell each individual part of that chili. They will smell the beef, the garlic, the cumin, the cayenne pepper, etc. This is because dogs can separate odors into their own individual items and smell certain drugs through things used to hide that scent. When a dog is sniffing the rate of inhale/exhale will increase from 15 to 31 to 140 to 200 times per minute. Another breathing technique specific to our hunting dogs is referred to as “air scenting” and is one long inhalation followed by an exhale through the mouth.

As new borns, puppies use their noses to find the mothers tit before their eyes open and

that scent bonds them to their mothers. A newborn pups sense of smell is developed even before their eyes open and their ears unfold. This is the same way dogs are able to identify their handlers even when blindfolded or dogs that are blind. Dogs have the amazing ability to remember odors. These memories from scent start in the womb; dogs can remember odors from before birth. A dog will be able to recognize his mother and the mother will be able to remember her puppies even after two years of being apart. There is evidence to show that dogs can even remember other scents longer than three months without that scent. Odors learned when young are remembered very well so its important for us to begin scent training early.

Even though dogs have much greater noses than we do, it is our job to teach the dog what scents we want them to find. We must give our dogs the experiences they need to become interested in certain scents that an untrained dog wouldn’t notice. We want to form a positive associations with fur and feather so that our dogs will seek it out. We want to train the dogs to search for these scents in a variety of conditions. Even an object aged up to a week can be found but this needs to be trained step by step.

There are certain scenarios and environments that can benefit or hinder the dogs ability to intake scent. A major variable that we must constantly pay attention to is wind direction. When a headwind is present, it’ll be the easiest for the dog and we will do this mainly when we begin scent training. When a cross-wind is present it gives the dog experience in entering into a scent cone for birds and, for tracking, gives the dog experience in searching beside the track. Tailwind, depending on wind speed, is the most difficult for dogs but forces air-scenting dogs to bring their noses close to the track and work more slowly. A tailwind is important to use when tracking but for birds we will try to avoid this because it will cause the dogs to run up on the bird before they smell it. An example if this is temperature. Temperature plays a big part in how our dogs will perceive certain scents. Warm substances give off more odor in cold environments than that same substances in hot environments. What this means is that a warm bird in a cold environment will give off more scent than a warm bird would in a warm environment. It is also harder to find a cold substance when the surrounding temperature is also cold. What this means is that substances will give off stronger scent the warmer they become. The best way to describe this is how we can smell food stronger when its being cooked rather than being in the fridge. Another environment that will affect a dogs ability to track is a that on a hard, dry surface, less odor transfer will take place. Water is crucial in following a trail, depending on how much water. A dog can follow a trail better when the ground is moist. So when the weather is warm and dry it’ll be harder for the dog to track the scent and the odor will go away sooner than on a cooler, more humid environment. Also, a dog can follow an older track better on a humid or dewy morning. Odor molecules don’t dissolve well in water so even if you boil an object to remove scent from an object it wont be enough. You must use water in combination with soap or another fat-dissolving product to remove scent. As stated above, dogs can breakdown and perceive different scents that seem mixed to us. They can even separate two scents on top of each other, but research has shown that the top odor is perceived as important for the dog. This is important because when we lay a track we will be dragging the item behind us but our feet will be leaving a scent trail. Even if the dog can smell you he will be focusing on the top scent.

Always keep scent and wind direction in mind when training and watch your dog learn to be an expert at locating all downed game.