4 min read


Can Dogs Smell Poison?



4 min read


Can Dogs Smell Poison?


At some point in our lives, we will have come across detection dogs, for example, at an airport. A dog’s incredible sense of smell enables them to be able to sniff out illegal drugs, contraband, and even human blood. 

We will take a look at whether dogs are able to smell poisons and by poisons, we are referring to those substances that are poisonous in general such as chemicals or those that could be used to harm others.


Signs Dogs Can Smell Poisons

A dog can be trained to smell pretty much anything, poisons included. Those that work with dogs in relation to odor detection need to be well-aware of their dog’s behavior, and this takes a lot of skill and patience.

A dog that has been trained to smell out a poison will be able to paw or sit at the point that they’ve sniffed out the odor. A handler needs to be able to pick up on the chain of behaviors that a dog displays when he’s searching for this specific poisonous smell. If a dog displays a sign, then it’s more than possible that they have located the poisonous scent. Here are some examples of signs that dogs display:

  • A dog stops and turns their head, almost as if their nose has been pulled into a new direction.

  • A dog closely sniffs a target area.

  • A dog may exhale loudly when they have located a scent.

Other signs that a dog may display are the following: 

  1. Body freezing
  2. Walking back and forth
  3. Stiff tail
  4. Head turning.

Human behavior can also play an important role when it comes to a dog’s ability to trace a poisonous scent. For example, humans can signal by using their eyes, tightening the leash, or stopping and standing at a specific point.

Body Language

Signs to watch for if a dog has detected poison include:

  • Head Tilting
  • Whining
  • Sniffing
  • Body Freezing
  • Nose Licking

Other Signs

More cues that a dog will give if they have found poison are:

  • Sitting Near The Poison
  • Giving A Trained Behavior
  • Pawing At Their Handler

History Behind Dogs Smelling Poisons


Historically, a dog's sense of smell has been linked to their primitive and instinctive behavior and was primarily used for hunting. Humans started using dogs in the first settlements to help them hunt and case prey to catch and eat, working side by side together. 

Today and in most recent history, humans have started to utilise dogs' noses to help with policing and detection. With increasing amount of terrorsim and crime, sniffer dogs are being put to good use and harmful poisons are just another in the latest list of ways criminals have tried to attack others. Therefore the need for sniffer dogs to smell poison arose. 

Science Behind Dogs Smelling Poison


We know that a dog’s olfactory receptors are a lot stronger than ours. A dog’s nose is what enables a dog to make sense of their world. If we take a look at a dog’s nose in more detail, we can see that it is wet, and this wetness plays an important role in capturing scents. This wetness is, in fact, a kind of mucus that’s in the nose. You may see your dog lick their nose which keeps it wet, as this helps to continue their smelling ability.

So, what actually happens when your dog breathes in? Well, when a dog takes a breath, the air that they take in travels down two different paths. Some of it travels to their lungs, while some of it travels to the olfactory receptors in the nose. 

A dog’s nose has 300 million olfactory receptors where we have only 3 million. Additionally, a dog is able to move each nostril independently, so this means they can detect a smell and the direction that it is coming from. What’s more is that they also have a second olfactory system, which is known as Jacobson’s organ. This can be found at the back of a dog’s mouth, near the nasal cavity. This organ is there to pick up on hormone-related scents, such as pheromones that are linked to mating.

A dog’s sense of smell is much stronger than their sense of sight, and it is linked to a part of the brain that is primitive. It’s now clear why dogs' sense of smell was critical for their survival and why we can train them to smell scents such as poisons.

If we take a closer look at a dog’s nose, we can see that there are slits at the side of the nose. These slits are actually for exhaling. So a dog breathes in using their nostrils and breathes out via these slits. This creates an aura of scent, which enables a dog to be able to smell more than we could have ever thought.

Now consider a dog’s snout. The length can vary depending on the breed of the dog, and some dogs have longer and larger snouts, which allow them to filter and humidify the air around them, as well as move it quickly towards the receptors on their noses.

Any scents that reach a dog’s nose receptors are then purified and weighed up. To begin with, any air that enters the nostrils is split between the two folds. One of these folds is for detecting a scent while the other is for breathing. The air that’s linked to scents then meets with the scent receptor cells within a dog’s nose. 

Training a Dog to Detect Things


Dogs are born with a full sense of smell and this can make scent-related training a fun game to play. When you play scent-related games with your dog, you will find that you further improve and enhance their skills at scent detection. If you want to train your dog to detect substances, then here is a game that you can teach your dog to play (we recommend choosing something that isn't poisonous, for the safety of your dog):

  1. Make sure your dog is out of the room and place a piece of food in an open area.

  2. When your dog comes back, they will find it.

  3. Now hide food for your dog to find, and the dog will soon learn to search for their treat.

  4. The games teach your dog that treats are located by scent and the location can change.

  5. Eventually, place the substance with the treat, and with time, your dog will learn to associate that smell of the scent you wish them to detect with a treat/reward.

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Safety Tips for Dogs Smelling Poison:

  1. It's important for you to avoid accidentally ingest poison! So, ensure you hand it correctly and take the proper handling precautions if you are using live substances that could put you both at risk.
  2. Many substances that are poisonous to humans are also poisonous to dogs, so make sure to train in a controlled environment and be wary of the symptoms of poisoning in the event of cross contamination.

Written by Charlotte Ratcliffe

Veterinary reviewed by:

Published: 05/11/2018, edited: 04/06/2020

Wag! Specialist
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