Can Dogs Smell Underwater? (Drugs, Bodies, Things, or Even You)

can dogs smell underwater

A dog’s sense of smell is incredibly powerful due to them having over 300 million olfactory sensors in their nose. Humans only have six million. What’s more, the part of your dog’s brain that analyzes smells is 40 times greater compared to the human brain.

Given their amazing sense of smell, you might be wondering whether dogs can smell underwater, be it cadaver dogs for bodies, drugs, or even an escaped criminal. I’ve researched it all for you, so here’s the short answer followed by the detail.

Can dogs smell things underwater?  Dogs can smell underwater, with a sense of smell so powerful that it can detect many things underwater. Some canines such as police dogs are trained to detect people, drugs, dead bodies (cadaver dogs), and lost items underwater. 

This topic is incredibly fascinating to me, so I decided to conduct further research and share my findings with you. If you’d like to know how a dog’s sense of smell works to locate items and people underwater including how deep, how far, and how it all works, then read on.

How do dogs smell underwater?

A dog has two holes in its mouth that gives it the ability to draw in smells without the need to inhale. If a dog dives into the water and opens his or her mouth it can draw any scent in without inhaling the water.

This way the dog can detect and smell something underwater and find the location. It’s an amazing skill, and why dogs are used to detect bodies and drugs that have been submerged.

But how do you know when your dog has detected something in the water? It might be difficult to tell because dogs are always excited. But you may be able to pick up subtle behavior if your dog is sniffing out something near the water.

Your dog may make some twitching motions with his or her head. This helps your dog get a better handle of the object he or she is smelling. Then your dog will start sniffing and running around the water and you’ll hear plenty of barks and growls to try get your attention.

Pay attention to your pup so he or she knows you’re alert and you’re not ignoring the barks and growls. See if you can detect anything in the water. If the water is safe, take a dive to see if you can find what your dog is sniffing out.

Handy Hint: Dogs have such an amazing sense of smell that they can even smell for drugs that have been vacuum packed and put into oil drums.

How far can dogs smell underwater?

Studies have shown that trained canines can smell a scent as deep as 30 meters deep underwater. The 300 million olfactory sensor receptors in their nose allow them to do this. On each receptor, there are about 150 cilia which are tiny hairs.

A dog also has a vomeronasal organ (read more) which allows them to smell anything located underwater. The organ runs along the bottom of a canine’s nose and connects to the olfactory lobe and has an estimated 600 nerve collections.

can dogs smell things underwater
Our own dog appears to be able to smell a treat underwater with no training.

Can cadaver dogs smell underwater?

Since the 1970s cadaver dogs have undergone vigorous training to smell and detect bodies that’s located underwater. Studies have shown that cadaver dogs have 95% accuracy when detecting objects and bodies.

“Based on dogs’ greater olfactory ability to detect and process odors, this method has been used in forensic investigations to identify the odor of a suspect at a crime scene. The excellent reliability and reproducibility of the method largely depend on rigor in dog training.” (view source)

A cadaver dog can detect remains 15 feet underground, with the dogs being able to smell bodies that are 30 meters underwater.

When there’s a body in the water it moves around because of the movement of water. It will take time for people to dive into the water to try and locate the body’s whereabouts.

That’s why cadaver dogs are trained to detect bodies in the water so the canine can find it faster.

Even if a body is submerged in deep and murky water a cadaver dog will be able to smell it and find its location. This works best if the dog is at the level of the water. The dog must either be at the water’s bank or allow the dog to be on the boat when searching for bodies.

For even more accurate results handlers will allow the dog to taste the water provided it’s safe to drink. Dogs use their vomeronasal organ to detect chemicals in water and the air. They can also use this organ to detect a body in the water.

A trained cadaver dog can smell the difference between a human corpse and a decomposed animal. That’s because there are different chemicals found in decomposed animal and human bodies. Dogs can detect the differences between these chemicals.

You also get trained dogs that are used for search and rescue missions. However, these dogs are trained to find people who are still alive while cadaver dogs are trained to find deceased people.

Handy Hint: Did you know that most dogs can hold their breath underwater for 5 to 10 seconds. Drug and cadaver dogs will be trained to hold it longer though!

Can dogs smell drugs underwater?

Did you know that a dog’s sense of smell is so powerful that it can detect a spoonful of sugar in a million gallons of water? Therefore, dogs can be trained to smell for drugs like weed, cocaine, and heroin and chemical substances underwater.

The training process is difficult and only a certain breed of dog is used for the task namely Labrador Retrievers and German Shepherds. Dogs that are used for this type of sniffing task must be agile and fit because they’re trained to protect the environment.

Border patrol canines are important because they can detect drugs submerged underwater. Training sniffer dogs to be water dogs has helped secure borders.

Can you train a dog to smell underwater?

You can train your dog to smell things objects but you will likely need a professional to assist you with the task. Additionally, it may only work with certain dog breeds.

On the other hand, if you notice that your pooch has an exceptional sniffing gift perhaps you can look into training him or her to smell for underwater objects.

Sniffer dogs such as cadaver canines go through rigorous training so you may not be able to conduct the training at home (here’s how the police do it). It would be more complicated than the usual commands that you may have taught your dog such as “sit!” or “stay!”

How do you train a dog to sniff underwater?

Dogs will need real-life scenarios for training especially if they’re going to be used to detect bodies in the water. Trainers will use pig flesh for training sessions. Pig remains are used at various stages of decomposition because it changes scent which is vital to the dog’s training.

Handlers or trainers will hide the pig remains on land in various locations such as behind trees, rocks and bushes. The remains are then gradually moved towards a water source. After some time, the remains will be submerged a few inches into the water to get the dog accustomed to the changing scent.

The scent will rise to the surface of the water and the dog will detect the smell of the flesh. After a few months of training, the dog will let the trainer know when he or she has detected the scent of remains by running up and down the boat or banks of the water.

Furthermore, dogs can be trained to use different signals when they detect remains in the water.

When taking your dog out onto the water make sure he or she has a properly fitted lifejacket. You must never leave your dog unsupervised when working in the water. Make sure you can see your dog at all times.

Your dog must be comfortable with being on a boat and inside the water before training begins. You don’t want your dog to be under any kind of stress while working in the water.


Canines have many unique skills, but when you consider that dogs can smell underwater, it takes their appreciation up a notch… it’s an insane skill to have.

This is why they are such a trusted asset to law enforcement as you can see on some of the recommended links below.

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Marc Aaron

I write about the things we've learned about owning dogs, the adventures we have, and any advice and tips we've picked up along the way.

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