5 min read


What Can Dogs be Trained to smell?



5 min read


What Can Dogs be Trained to smell?


Oh, that wet and wiggling nose on your sniffer-ific best friend! It is so much fun to watch your dog taking in and enjoying the smells around him. 

You know you can find your dog nosing around in the trash, your laundry, the kitchen table, and the bushes outside. And a ride in the car is just a real thrill to his senses as new smells explode in his nose! 

These natural instincts to love smells make your dog an asset to people who work with canines as teammates in work, sport, or helping others. Dogs can be scent trained to track and find bombs and explosives, chemicals and drugs, criminals, wildlife, cadavers, disease and changes in the human body, such as cancer and seizures. 

They are a powerful ally in helping mankind. Let’s explore how your dog’s natural instincts and intelligence can be developed through training.


Signs Your Dog is Learning a Scent

You can watch your dog when he is detecting a scent. Your first sign will be your dog’s focused attention. Their attention is on the new smell. When a dog has been trained to detect a sense, he will pull hard and with energy to track and find the source of the smell that he is taking in through his super-sensitive nose. 

The dog will be going directly to the sources that will give him the best intake of sensation. Checking for drugs at the pier? The dog will be going directly to the luggage lined up for inspection. Checking for landmines? The dog will be sniffing the ground. Hunting for quail? You will see your dog bound to the bushes to sniff out the bird.

Other body signals that your dog is on a scent will be found in your dog’s heightened level of activity and physical tension. They will be moving quickly and will often be pulling so hard that it can be difficult for the handler to keep up with them when they are on a scent. 

You will see your dog engaged from the tip of his nose to the tip of his tail. Some breeds will actually physically point to the location of the scent. The point can be observed when the dog has the nose lunged forward, a front paw lifted and the extension of the tail. Literally, the dog is stretched into a point that shows you the source of the scent. 

Of course, breed and training may lead the dog to have different signals to you when the scent is found. For example, a dog may be trained to bark when someone is about to have a seizure or become hypoglycemic. It will be clear to the handler that the dog has localized the scent when he remains focused.

Body Language

Here are some signs that your dog is actively following his training to detect a targeted scent:

  • Staring
  • Alert
  • Barking
  • Sniffing

Other Signs

By watching your dog during scent detection, you will also see these signals of his scent detection in action:

  • Pulling Hard On Lead
  • Body Tension
  • Pointing With Tail
  • Pointing With Paw

The History of Dogs Learning Scents


The evolution of the man and dog relationship is thought to have begun when humans raised wolf pups. The dogs helped humans to hunt for food and warn of approaching danger, and they subsequently became companions. Breeds of dogs evolved out of the working relationship with man.

In contemporary times, it is thought that scent detection work with dogs become increasingly important and popular by the mid-twentieth century. The first official American bomb dogs came into use in the 1940s for the purpose of detecting German mines in North Africa. 

The use of dogs for scent detection expanded such that by 1972, dogs in the United States were being trained to identify explosives and illegal drugs. The drug dog programs started with marijuana, heroin and cocaine. More currently, dogs are also trained to detect ecstasy and methamphetamines. 

Dogs have been widely used for other police activities, such as detecting cadavers on search and rescue missions. Today the Department of Homeland Security has standards for training scent detection dogs.

Scent-detection dogs are fulfilling a need for persons with disabilities. These dogs have been trained to alert individuals when they are about to experience a serious health crisis. Scent dogs can be trained to detect cancer, diabetes-related health problems, seizures, heart attacks, and migraines. For persons with serious allergies, they can be trained to detect substances that are dangerous to them, such as allergens and mold.

Since 2011, dogs have been used to detect bedbugs. Bedbugs are insidious and difficult for exterminators to locate. Beagles have been trained to come in to find the bedbugs, bringing needed help and relief to communities suffering from the infestation. In fact, in 2011, the National Pest Management Association established that the utilization of trained dogs is a best practice in bed bug management and set industry standards for the training and certification of canines!

The Science Behind the Sniffer


Unlike humans, dogs take in smells separately from each nostril. The dog’s nose serves two purposes - breathing and scent detection. 

Different from humans, dogs have a special olfactory organ called the vomeronasal organ, also known as Jacobson’s organ. This special organ is located in the bottom of the dog’s nasal passage. Your dog has an amazing sense of smell that is 10,000 to 10,000,000 times more powerful than the human sense of smell. This amazing ability makes the dog especially talented to be used for scent detection and to be trained to detect smells.

Over time, breeds of dogs have evolved who are especially talented at being trained to detect scents. Typically, these are the breeds commonly used for hunting and guard work. The breeds best known for their scent detection abilities include the Bloodhound, Basset Hound, Beagle, German Shepherd, Labrador Retriever, Belgian Malinois, English Springer Spaniel, Coonhounds and Pointers. 

This does not mean that other dogs can be trained to be astute sniffers. Dogs can vary because of breed, personality, and training opportunities.

Training Your Dog to Detect Scents


You can train your dog to detect scents by applying good basics of dog training. Use a lot of positive reinforcement, including praise and treats when your dog is approximating the behavior you want him to do. Make training fun! Scent detection trainers invent games that are interesting and fun for the dog but also are increasingly complex in building on the dog’s ability to search for and detect the target scents

Police dogs are trained to detect drugs. Some people think the dog is attracted to the drug, but that is not what the dog is doing. The dog is actually looking for a toy! Yes, the police dog trainers will play games with the dog in which the dog is searching for a fun toy with the scent of the drugs. The dog and trainer play hide and seek with the toy. The dog receives a lot of praise and reward when he is able to find the toy.

As part of the training, the dogs learn how to alert the handler when they have located the scent. With aggressive alerting, the dog is trained to paw and scratch at the location of the scent. The aggressive alerting is desired when searching for drugs. 

It would be dangerous for a dog searching for a bomb to scratch at the bomb. These dogs are trained to engage in a passive alerting behavior, such as going into a sit. The behavior is conditioned using chaining, which is a technique in which the alerting behavior is linked to the finding the scent. The dog is taught what to do when he finds the scent through repetition and rewards are given for the proper alerting behavior.

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Safety Tips While Scent Training:

  1. Do not let your dog eat toxic substances
  2. Train in areas that are safe where you can control the environment
  3. Teach your dog the alerting behavior to protect him from harm when he locates the scent

Written by a Cavalier King Charles Spaniel lover Pat Drake

Veterinary reviewed by:

Published: 01/29/2018, edited: 04/06/2020

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