Scent Discrimination
At Dog Scout Camp, we periodically learn skills which involve the dog's ability to distinguish scents. Search and Rescue, Scent Hurdle Racing, Tracking, Scent Discrimination and Drug Detection are a few of the activities which have been featured that include "nose work."
A dog's sense of smell is more powerful than we can possibly imagine. They can easily detect the presence of one drop of blood in a 55 gallon drum of water. Tests performed back in the 1950's by Neuhaus, it was concluded that dogs "Having an olfactory acuity which is from 1,000,000 to 100,000,000 times that of man, a dog can detect one mg of butyric acid in 100,000,000 cubic metres of air, the "volume', said Neuhaus, of a whole town." (Olfaction and Odours by William McCartney).
I'm not so sure how they measure all of this stuff, but I'll concur that dogs have one heavy-duty sniffer! Scent work is easy for the dog. The hard part is communicating to the dog which scent it is we want them to discover. And then, once we are able to show them which scent we want them to find, how do we MAKE them want to find it? In the "dark ages" of dog training, there were all kinds of people employing force methods to try to make dogs reliable at scenting. I maintain that the FASTEST and most reliable method to teach a dog to do scent work is with operant conditioning (click and feed).
Here are several "Games" to teach your dog to use his nose to find the things that YOU want him to find.
· The Substance Detection Game
A good exercise to get your dog used to using his nose is the "find it" game. Take a cookie and show it to your dog. Let your dog watch you as you go around looking for a place to hide it. Pretend to tuck the cookie away several places before you surreptitiously leave it in one of the places (between the couch cushions, under a pillow, or behind some furniture). Then, let the dog begin looking for it, with the words, "Find it!" When he finds it, make a big fuss over him as he eats the cookie.
When he gets used to this game, you can switch to hiding the goodie in a film canister with holes drilled in it. The smell of the cookie will be able to waft through the holes, and the dog will not be able to help himself to the cookie when he finds it. He has to have you there to open it for him and feed him the cookie. Then, start hiding the canister while the dog is in another room, so that he can't see you, and doesn't have any "hints" as to where to look. He will walk around "checking" all of the favorite hiding spots with his nose, until he finds it.
This exercise is used to teach your dog to discriminate one scent from another, as in Utility (obedience) scent discrimination. You will need five or more identical articles. I use metal to start off with. You could use spoons, empty V-8 cans, or regulation obedience scent articles. I started out using metal bobbers--the kind that are used on fishing nets on the great lakes. They break loose and bob their way to the beach, and I've collected them over the years. They look like six inch long, inch and a quarter in diameter sausage with ridges. You will want to number the articles, or otherwise identify them, so that YOU will not get confused as to which one is the correct one.
To begin with, get some treats and a clicker and one of your articles. Choose one article and note the number. Toss the article and get the dog to fetch it and bring it back. When he brings it to you, click and feed him. Touch the article with the same hand you are using to touch and break up the treats. The article should smell like your hands, which smell just like the hot dogs, or whatever you are using as a treat. Start throwing the article where the dog has to look for it a little (with his nose), like under the couch, behind the trash can or whatever. Keep tossing the article to different locations and reward his "selection" of the right article when he delivers it to you. When the game starts to get so easy it's boring, take a "clean" article and place it out in the middle of the floor. Then, toss the scented article, as usual, and have it land about 5 feet away from the unscented article. When the dog makes the correct selection (he may not even see the other article), and delivers it to you, click and feed, as usual. Do NOT click as the dog hovers over the correct article. You don't want to "help" him by doing all of the thinking for him. You want to reward him by making a selection and committing to the correct article.
When you add an unscented article, it's kind of fun to "keep score," noting each correct response or incorrect response. I just note a little "C" or an "I" on a piece of paper, and whether the "test" was one article, two, three, or four. If the dog chances to pick up the wrong article by mistake, you do not utter one word. You do not tell him he's "wrong." When he tries to deliver it to you, you simply don't take it from him, and you don't click and feed him. And he gets one "I" on his "report card!" You will note how quickly he learns to make the correct choice, and how the "C's" become more prevalent, and the "I's" become non-existent. If he presents you with the wrong article, and you ignore him (don't even look at him), and he goes and picks up the correct article, smile, and when he presents it to you, click and feed. But that entire response still gets recorded as one "I."
Toss the scented article within 5 feet of the unscented one at least 5 times. If he gets one incorrect, then start again, until he can do it five times in a row correctly. When the exercise seems so simple it's boring, toss the scented article to land within 4 feet of the unscented one. Follow the same procedure as you did before. If the dog should pick up the incorrect article, you might want to replace it with a new "clean" article, because he might go for it again, because it has his mouth (complete with hot dog) scent on it. When he gets five correct responses in a row at 4 feet from the clean article, start tossing it to within 3 feet of the clean article. As you do this, toss to all different sides of the clean article, north, south, east and west. Chances are, you'll have some bad throws, and accidentally have the scented article land closer than expected to the clean one. That's ok. Just try to be more accurate with your toss next time. You don't have to toss it far. You can do this entire exercise in you living room, sitting in a chair and lobbing the articles a mere 5 feet or so in front of you.
When you get to success at throwing the scented article within 2 feet of the unscented one, it's time to add a second unscented article. Before you do this, though, make sure your dog has reached the point of noticing the one "clean" article, and rejecting it. He should have had this opportunity at least several times. If he hasn't, then keep moving closer with your scented and unscented article, until he has to choose. When he has made five of these correct choices in a row, then it's safe to add a second unscented article. Continue as before, tossing the scented article within one or two feet from the clean one, and if the dog makes a mistake, let him figure it out. Ignore him, and refuse to take the incorrect article from him. By now, he should be on the program, and say to himself, "something is wrong with this picture." He should then realize that to get the "payoff," he must go back to the articles and find the correct one. Any time he gets the incorrect article, just let him choose again, until he finds the correct one, and reinforce him. Even if he brings back every article but the correct one, be patient, and wait for him to bring you the correct article, and reward him.
Again, when he is getting five correct responses in a row, up the ante by adding another clean article. Continue as before and add another. Pretty soon, you'll be working with an entire set. Next, begin turning your dog around, so that he does not see where you place the article in the set. This will tell you for sure whether he's using his nose to look for it, or just relying on visual and auditory cues to "mark" where it lands. If you have a regulation set of articles, consisting of wood, leather and metal, then you can continue to add the wood and leather, while you are working on the first metal one.
Now, you may think that you've successfully taught your dog to do scent articles. No, you've only taught him to find a correct "metal" article among other articles. Now, you have to go back to square one and begin teaching him to detect the correct wood and leather articles among the others. Metal was the easiest, because it doesn't harbor the scent of other things as long (it's less porous), and it doesn't carry as much of its "own" scent.
Just last week, I taught my young dog the metal scent article. Within 45 minutes, she was correctly picking out the scented article from a group of 16 - five metal, five leather, and five wood (plus the one scented metal article). This method is easy, fast and effective. You don't need special equipment, like tie-down boards (which I feel only teach the dog to "test" for the loose article, instead of using his nose). There is no admonishment or "hint" given at the wrong or right choice (which I feel teaches the dog that YOU'LL tell him when he gets close to right article, and he doesn't have to learn to do it himself). With this method, the dog learns to discriminate with his nose (which is EASY for him), which article will earn him the reinforcement (the one with your scent on it). If you feel that 45 minutes straight is a long time to "press" a dog to learn a new behavior (I did), perform a little test. Don't put the scented article out there, and just sit back in your chair, like you're saying, "That's all--I'm done," and see what your dog does. If he runs back to the pile of articles to continue the game, he's not ready to quit yet. That's the beauty of clicker training. It's not hard on the animal--it's all fun. If you're doing it right, he won't want to stop.
Your dog does not have to be destined for the Utility obedience ring to learn this exercise. The youngest dog I have ever taught successfully to do the scent discrimination was a 13 week old puppy. Since it's nothing but a game, you don't have to wait for your dog to reach some magical age of physical maturity. If he's got a brain, a nose and a stomach, he can quickly learn the Scent Discrimination Game.
You don't have to work for the police department to teach your dog to detect a particular substance. Canines are at work all over the place detecting such things as natural gas leaks, endangered turtle species, mushrooms, cancer cells in patients, explosives, dangerous snake burrows, excellerants, drugs, termites, contraband agricultural products, bodies buried under avalanches, and drugs, to name a few. You could train your dog to detect dirty baby diapers, gypsy moth nests, or peanut butter, if you wanted to. It's all up to you.
I will share here the method that was presented to us at Dog Scout Camp in the summer of 1999 by William Burt, a civilian who has worked with police canine units and the military, training and using detection dogs. Bill is from
With substance detection dogs, you need to create a motivation for them to look for the drugs, so the first step is to make a game out of playing tug-of-war and fetch with an object, which is called a "giftie." The giftie can be a cylinder made of PVC, in which scented materials can later be inserted. The cylinder can then be wrapped with a towel, and bound with string, to make it more inviting to the dog. You want to make the giftie the favorite toy for the dog. He only gets the giftie when you allow him to have it because he's done something great. It becomes what he lives and breathes to do.
You need to select a scent that you will have your dog detect. This could be interesting. I suppose in the early days, people were forced to use illegal substances to work with their dogs. But now, there are these interesting things, called "pseudo chemicals," which simulate the scent of the REAL drug or explosive, so that trainers don't get in trouble with the law by using the real thing. If you can't get your hands on pseudo chemicals (and don't ask ME, I certainly don't know where to get them), perhaps you should start with something like termites, or mushrooms, which could actually prove to be far more valuable to the average civilian in everyday life!
Take the pseudo chemical, or real scent of the target substance, and place it on some cotton inside the PVC tube (the tube has holes in it, so that the smell can radiate out). Play with the giftie as usual, throwing, tugging and hiding it for the dog to look for. The dog will start associating the scent with the presence of his favorite toy. Then, begin hiding it in more and more difficult to find places, when the dog is not in the room. He will have to search the whole room to find his toy and start the "game."
Now, in real detection work, the trainers have to teach their dog a signal, which means "the smell" is present. Different kinds of alerts are used for different kinds of substances. For instance, in the airports, the members of the "Beagle Brigade" (dogs which sniff out illegally transported agricultural products) are taught to indicate the presence of the substance with a "sit." It wouldn't be very polite to start scratching and barking at someone's nice luggage, or their fanny pack! It would attract a lot of attention, too. So the dogs just sit when they come to a piece of luggage which has suspicious scent coming from it. Sometimes you might want the dog to "scratch" to indicate the presence of the target smell. This type of indication might be used in recovery of buried bodies, drug search, or natural gas leaks. It pinpoints the source of the smell, but it can be rough on woodwork, luggage, or something else you don't want to disturb (like bombs).
To teach the dog to sit when he detects the smell of your target substance, you must first be able to predict when he has located the target substance. You could start with a cardboard box with some holes in it. Place the scent laden giftie under the box and bring the dog into the room. When he finds the giftie, hidden under the box, he is going to want to try to get it out. Cue him to sit, then take out the giftie and play with him. So, he learns that to "turn on" the game, he must sit at the location of the giftie.
To teach "scratch drills", you have to teach the dog to paw at the target. Bill showed us how easy it was to teach a dog to touch the end of a target stick with his nose to earn a click and feed. When the dog pretty much thinks he's got it, you stop rewarding the nose touch with the click and food. It's amazing how quickly the dogs make the quantum leap to use their paw, instead, to touch the stick. Driven by frustration, they eventually paw the touch stick, and you once again click and feed. When you get a pretty strong pawing or scratching behavior, you can point the end of the touch stick at anything you want the dog to paw or scratch. In the box drill, described above, you would do the same thing, but you would cue the dog to scratch the box before getting the giftie.
When the dog has the complete search, find, and indicate behavior, you can name the behavior. My dogs already know the word "find" in association with using their noses, so I used the words, "Find Drugs" (we were using pseudo cocaine at camp). Seeing how readily my dog learned to detect cocaine, I decided to put her to use finding something much more useful in my everyday life, like Gypsy Moth egg nests. We live in the forest of northern
I met an interesting man from
For Search and Rescue, a dog must be trained to find the scent of a human. One game you can teach your dog to prepare him for this is the "Find Bubba" game. You would use the name of the person you actually want the dog to find.
First, you have to make an association between the name and the person it belongs to. With you and your target "victim" sitting in the same room, ask your dog to go "find Daddy!" or whomever. Have "daddy" call the dog to him and give him a treat. When the dog starts associating going to the target person with getting a treat, you can start making it more difficult for him to find the target person. Have your person hide in the other room, and then tell your dog to "find daddy!" When he finds the person, give him a treat. The treats have to stop coming from the target person, otherwise what you may be teaching the dog is to "find the person with the treats." This would be no good if your lost child didn't happen to run off with his pockets full of dog treats.
Eventually move outdoors, and have your "victim" hide in the immediate area. Let your dog watch the person disappear into the search area. The process by which your dog is finding the person is called "air scenting" (as opposed to tracking, where the dog is trained to look for each footstep of the person he is trailing on the ground). The dog will cast about, with his nose in the air, trying to catch wafts of scent rafts floating on the breeze. When he finds your person, click and feed, and make the next "find" a little more difficult. When the dog is making this look too easy, start turning him in a circle just before you let him go after the person (so he loses sight of his memorized "last point of sight"). Then, go to having his back to the hiding person during the whole hiding part, and eventually, have the dog completely out of the area when the person goes to hide.
This game is not as difficult or time consuming as it might seem. My roommate at a Volhard Instructor's camp (about 20 years ago), Jeannie Collins, taught her Golden Retriever, Tess, that I was "Lonnie," then, as part of a contest to see who could shape the best trick during the five-day camp she demonstrated how she could send Tess on a "find Lonnie" from our cabin to the main lodge, where there was a "social" going on, and Tess worked her way through the room and past all of the food, to find me amongst hundreds of other people. This behavior was developed over just a few days of occasional practices. A cute "parlor trick," but you could see where something like this could be eminently useful.
