4 min read


Can Dogs Smell Drugs in Water?



4 min read


Can Dogs Smell Drugs in Water?


Everyone knows that dogs have an amazing sense of smell. Evolution has enabled dogs to have an olfactory system that makes them incredible at tracking down scents. Not only does this make them superb hunters, it can also help humans with issues where we require a superior sense of smell. 

A dog’s sense of smell is so sensitive that it is able to smell through different materials, and that includes water. For this reason, dogs are very useful when it comes to investigations such as locating a missing body. We will now take a look at how this astounding sense of smell enables dogs to identify substances such as drugs in varying circumstances.


Signs Dogs Can Smell in Water

If a dog can smell something in the water, they will act in the way that they would if they’d discovered something exciting. A dog will seem very alert and become focused on a specific area. They will wag their tails and their ears will rise. In a situation where a dog is swimming in water where they’ve located a substance, the dog will circle the area or keep returning to that area. 

At the same time, the dog will make sure that their owner realizes their find in a specific way, by displaying behaviors if a substance is discovered. These behaviors include laying down, sitting, or stopping at the site. If instructed to, a dog may even provide an audible sign. If a dog has not been trained to identify an exact substance, they will still show that they’ve found a scent that interests them.

Aside of being alert, a dog may bark, whine, and growl, or do whatever they can to alert you and get your attention such as pawing, trying to take you to the area where they have smelled something, or jumping on you.

When it comes to breeds of dogs, there are some breeds that are naturally better with smells, such as German Shepherds, Basset Hounds, Beagles, and Bloodhounds. For this reason, these breeds are used as security or police dogs, as they are extremely good at detecting smells in difficult scenarios, including in water.  

Body Language

Some signs your pooch will give if they have made an aquatic discovery are:

  • Barking
  • Whining
  • Jumping Up
  • Sniffing
  • Raise Ears
  • Ears Up

Other Signs

More signs to watch for if your dog has smelled something in the water are:

  • Circling An Area
  • Displaying A Trained Cue
  • Pawing At You

History Behind Dogs Smelling Drugs in Water


Dogs are known to be able to detect objects and substances such as drugs that are located in different materials. For this reason, dogs have always been beneficial in criminal investigations.

At the time of the Jack the Ripper case, Bloodhounds were used by London’s Metropolitan Police to locate him. This then led to the idea that dogs would be a useful asset to assist with criminal situations and investigations.  

By the twentieth century, countries such as Germany, Austria, Belgium, and France developed groundbreaking methods that employed the smelling ability of dogs. When it came to identifying and scolding criminals, German Shepherds were believed to be the ideal dog.

As time continued, using dogs in policing became normal practice. Dogs were trained to recognize certain scents and to respond to instructions and behaviors that were hostile or violent. This means that dogs can now help in many situations, such as detecting drugs and other substances that are illegal, locating explosives, helping in search and rescue missions, supporting military staff, and reprimanding criminals. Additionally, dogs can now also be seen in security situations, military points, public events, and airports.

Science Behind Dogs Smelling Drugs in Water


A human has 6 million olfactory receptors whereas a dog has 300 olfactory receptors, both around and inside its nose. In dogs, the part of the brain that interprets smells is 40 times stronger than it is in a human.

A dog’s physiology is also naturally able to analyze smells. As humans, we have just one route - the nose, which not only smells but also helps us to breathe. Dogs, on the other hand, have a separate system. One route from the nose delivers air to the dog’s lungs and the other route is purely for smelling. In a dog, the olfactory receptors and the brain work hand in hand to analyze what it smells, and can then make connections based on what experiences have taken place before.

In fact, a dog’s sense of smell is so powerful that in a million gallons of water, they can smell a tablespoon of sugar. So it becomes clear why they can locate small amounts of substances such as drugs in a search and rescue situation where large amounts of water are concerned.  

Training a Dog to Smell Drugs in Water


Training a dog to smell drugs through water can be a difficult and lengthy process. Firstly, the most appropriate breed of dog needs to be used. Once the correct puppy has been selected, training begins by making the puppy obedient. The puppy will then be trained to respond to specific gestures and voice commands, and positive reinforcement is used for rewards. If the puppy that’s been selected is hard to control at this point, it seems unlikely that they will progress in their training

A dog that undergoes this kind of training needs to be fit, agile, confident, able to work under menacing circumstances, and have no ailments that affect their physical performance. If these aspects are all in place, the dog is ready for training.

Play is the method used to train a dog to identify drugs. To begin with, the dog is taught to play tug of war using a clean towel. Next, the drugs are bagged up and wrapped inside the towel. In time, the dog will start to link a certain smell with the towel and the game. In a scenario where the drugs are detected in a different location, the dog will attempt to play the game of tug of war, and this is the way criminal activity is identified.  

When training a dog, bear in mind that each dog is trained to only perform one kind of search, as they are not able to tell their handler exactly what substance they have located.

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Written by Charlotte Ratcliffe

Veterinary reviewed by:

Published: 04/18/2018, edited: 04/06/2020

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