Man’s best friend has quite the sniffer. A dog can smell anything from a family member to an escaped convicted who has gone into a river. They have a superior smelling ability when compared to humans.
How far can a dog track a scent outdoors? Some bloodhounds can track a scent trail up to one hundred and thirty miles. Other dogs can track a scent from anywhere between five and fourteen days. The broad range of days is due to environmental factors. Training can also be a factor in lengthening a scent dog’s tracking distance.
Dogs have the ability to use their noses to get home when they are lost. They also can sniff out cadavers, escaped convicts and missing persons. But there are several variables that can help or hinder a dog’s ability to catch a scent. We’re going to explore all the variables that impact how far can a dog track a scent outdoors in the article.
How Does a Dog Smell?
A dog has two air passages in its nose. One of the passages is used for inhaling air, and the other is used for smelling. About twelve percent of the air that a dog breathes in goes through the smelling chamber.
“We found that when airflow enters the nose, it splits into two different flow paths, one for olfaction and one for respiration.”
Brent Craven, bioengineer at Pennsylvania State University
When a dog exhales, the pressure of breathing out actually helps guide new odors into the dogs’ nose. In a sense, a dog constantly smells regardless of whether they’re breathing in or out. And if that weren’t enough, their super sniffer possesses up to three hundred million olfactory receptors. Humans only have about six million receptors.
Besides having fewer receptors, you can’t wiggle your nose without touching it as a dog can. Because their nostrils work independently of each other, a dog can tell which nostril the scent came in. This lets them know what direction the smell is coming from. That’s why you see a dog weave back and forth when they’re tracking.
Dogs also have an olfactory organ that we don’t have. They possess an organ called the Jacobson’s Organ. This is similar to having a second nose.
This second nose is located at the bottom of a dog’s nasal passage. It picks up pheromones.
The Jacobson works independently from the other odor molecules. It has its own nerve system. You might have been walking your dog and notice them stop and sniff the air. Your dog is probably decoding something interesting to them that neither of you can even see. A dog’s nose works as your eyes do. They obtain information through their sniffers.
How Far Can a Dog Sense Its Owner?
You’ve probably heard the stories of dogs walking miles to get back home. There’s a powerful urge for canines to be with their families.
Once when a dog was adopted, it walked eleven miles to be back with its original foster family. What makes this amazing is that the dog had been taken to its new home by car. It had only to use scent to get back to its former family. So how far can a dog smell home?
“An eleven-mile distance is actually not terribly long for a dog,”
Bonnie Beaver, the Executive Director of the American College of Veterinary and Behaviorists
If the dog had walked on its own, it would follow its own scent back, but, in this case, it followed its former owner’s scent. The dog-human bond is powerful.
You can actually train a dog to identify the smell of your family members. You do this through repetition and reward. When you reward your pet, they take in your scent. They equate your scent with a good thing.
Often those who use sporting dogs will work to create a “scent” bond. They want to enhance the bond with the dog to create an ally when there’s a scent/chase/kill activity.
How Far Can a Dog Smell in Miles?
There are a few factors that influence how far a dog can smell in miles. These include:
- Wind speed
- Wind direction
- The density of objects between dog and scent
- Weather
- Training
- Temperature.
Hot, dry summer months are tough for a tracking dog. A dog’s nose performs best in the spring and fall when the ground is cooler than the air.
Light rain actually enhances the odor.
And for that convict escaping from the law. Jumping in the river won’t help your escape. A dog can smell something in the water without even getting wet.
A dense object like concrete is no match for a dog. A trained dog can smell a cadaver under cement at least fifteen feet down.
How Far Away Can a Dog Pick up a Scent?
Depending on the weather, a trained dog can detect a scent between fifty and five hundred yards away. However, if the weather is severely bad, a hundred yards might be pushing it.
A dog can probably smell a person forty yards away, standing upwind on a windy day. But under the right conditions, their nose can pick up something even further away. So how far away can a dog pick up the scent? One experiment showed a mile away.
A Dog Sniffing Experiment
An experiment was used during a training session for detecting orca waste.
Dogs are often used to detect whale poop and other endangered species waste. The dog stands on the boat’s bow and hangs their head over the water sniffing. A dog on Puget Sound detected the whale poop from a mile away.
“It is amazing, these dogs get in the wind cone so to speak, and when he gets the scent the dogs go into position. Once they’ve smelled it, they do not break concentration until they get there.”
Jenny Atkinson, Whale Museum in Friday Harbor
Once the waste is identified, the dog signals which directions to go. And of course, the pup gets a reward for her trouble.
The Top 5 Best Scent Dogs?
- Bloodhound
- Basset Hound
- Beagle
- German Shepherd
- Labrador Retriever.
1. Bloodhound
This scent dog was originally bred to track boar and deer. They have since been used to track humans. Bloodhounds are used in law enforcement and are so reliable their results can be used in court.
It has been estimated that their sense of smell is one thousand times stronger than human’s.
When a bloodhound smells an article of clothing or any other intimate belonging of a lost person, an odor image embeds itself on the bloodhound’s brain. It’s sort of like taking a picture of the odor. The dog is then able to track the scent.
The bloodhound has other characteristics besides a killer nose that helps them track. These include:
- Wrinkled skin—this is used to trap the odors;
- Ears that droop—they drag on the ground and push the scents toward their noses;
- Great stamina—they can track for long periods of time.
The bloodhound can smell odors up to three hundred hours old.
2. Bassett Hound
The name Basset is derived from the French word bas. This means low. And thus, the Basset Hound is justly named.
The Basset Hound has over two hundred and twenty million smell receptors. And the part of their brain responsible for smell is forty times bigger than humans.
3. Beagle
These fun little dogs have impressive sniffers. In fact, they’re ranked third when it comes to breeds with the best sense of smell. They have forty-five more scent receptors than a person. They also have a long sturdy neck that allows them to easily put nose to the ground.
Their short legs help them stay closer to the ground.
4. German Shepherd
German Shepherds are best known for tracking drugs and bombs.
When a German Shepherd smells drugs, they elicit an aggressive alert. They dig and paw at the location because they smell the drugs.
For a bomb dog an aggressive alert could be disastrous. You don’t want a dog digging and pawing on a bomb. The shepherd has a passive alert for these occasions. They simply sit down when they smell a bomb.
5. Labrador Retriever
A lab’s great sniffing ability starts with the shape of its nose. Most dogs have flat faces. As a result, they have short noses. A lab has a bigger, longer nose. As a result, they have more space for olfactory (smell) receptors. They also have bigger olfactory bulbs in their brains.
Not only are labs good sniffers, but because they are so responsive to their handlers, they can be some of the best tracking dogs.
Labs have several uses. They can:
- Detect tumors
- Detect cancer
- Detect possible oncoming seizures.
They can do this because they can tell the difference between a healthy person and a sick person. They accomplish this by sniffing out chemical compounds. These compounds are released in sweat or other fluids.
Honorable Mention: the Pit Bull
You may not think of a Pit Bull as a scent dog, but they have an acute sense of smell.
The best sensory organ of a Pit Bull is its sense of smell. Because of this great sense, it can follow 1-week old trails. A Pit Bull can sniff out smells that are diluted to one-millionth the concentration. Like the Beagle, an un-neutered male can smell a female in estrus up to three miles.
As a point of clarification – what is a Pit Bull? It’s a shortening of the long name “Pit bulldog”. Like the term “hound”, “Pit Bull” refers to a type of dog that has come to include these distinct pedigree breeds:
- American Pit Bull Terrier
- American Staffordshire Terrier
- Staffordshire Bull Terrier
- American Bully.
Pit Bulls also make great hiking companions.
Working Scent Dogs
There are many types of scent dogs. From Cadaver to search and rescue, these special dogs work to protect people.
Some of the jobs that these great sniffers do include:
- Cadaver dogs
- Disaster dogs
- Water and search dogs
- Air scent dogs
- Avalanche dogs
- Trailing dogs
- Detection dogs
- Tracking dogs.
These are all important jobs, and it could lead to a possible societal breakdown without these unsung heroes.
1. Cadaver dogs
These dogs can detect minute scents of human remains. They can even track blood drops.
In order to train cadaver dogs, certain chemicals that mimic human remains are used. Only an authorized trainer can obtain these chemicals.
These dogs can smell human remains below concrete, soil or water.
Although this job is a little on the macabre side, these dogs have been able to solve crimes. They have also been able to give closure to families who have lost loved ones.
A cadaver dog is usually right. How right? Well, ninety-five percent of the time a cadaver dog is right on the money. If they say there is human remains deep underground, they’re probably right.
“So, if a dog says it’s there, there’s a darn good chance it is. They’re pretty accurate.”
Sharon Ward, a cadaver dog trainer.
Cadaver dogs are close to their handlers and often live with them. They are considered officers of the law. Interfering with a cadaver dog is a serious offense.
2. Disaster dogs
These dogs have to be able to not only work off the lead but also in tightly confined areas. They are often on unstable surfaces.
They find humans if the most horrendous catastrophes. Be it a building collapse or an earthquake, disaster dogs have to be and are prepared for any situation. Many people have been saved because of these dogs.
3. Water and search dogs
These dogs are attuned to gases from decomposing human remains that rise up from under the water. They hang off the bow of the boat, sniffing the water. Water and search dogs work with not only their handlers but with a diver.
4. Air scent dogs
Air scent dogs don’t work with a scent sample. They basically just stick their nose in the air and sniff at traces of human smells that are drifting around. They don’t follow a ground track.
The downside to an air scent dog is they may not be able to differentiate between who they are looking for and the people around them. But they are capable of disaster work. Generally speaking, they work off lead.
5. Avalanche dogs
A trained dog can smell through barriers. Avalanche dogs can smell humans buried under snow. They can find cadavers. However, they have been able to save quite a few people who were buried alive.
6. Trailing dogs
Trailing dogs are given an article of clothing or any other item that the missing person has come in contact with. They are then able to follow a trail of this scent. It is based on tissue cells that remain in the article. They can only track if they are given this scent sample.
7. Detection dogs
These are your bomb and firearms dogs. They are used by police, military, customs, and counter-terrorism agencies. Some are also used to detect drugs.
8. Tracking dogs
Criminals beware. These dogs are out to get you. Tracking dogs are able to track without a scent sample. They are capable of tracking the path of any person.
Do You Want to Teach your Dog to Track?
You and your pooch can have fun learning to track. Dogs think it’s a game, so treat it as such. It’s not difficult to teach your dog to track by scent. It comes naturally to them. There are several steps you can take which include:
- Crack of dawn training
- Treat trail
- Ask for the treat
- Increase the trail.
Before you start, make sure your dog has mastered “sit” and “stay.” You might be tempted to push ahead but get the basics first. Smelling is natural for a dog, so tracking won’t be difficult.
1. Crack of dawn training
OK, you don’t have to get up at the crack of dawn, but you do want to do this in the early morning.
You should choose a grassy area.
And the reason you want to be there early is, so few people have had a chance to walk on the grass. The magic hour is about 6 a.m.
2. Treat trail
With a hotdog or other type of food, periodically smash an inch-long piece into the soil with your shoe as you walk away from your sitting dog. You want to make sure you really push the hotdog into the grass. A grassy smell should be released.
Then walk away from your dog.
The hotdog will be on the bottom of your shoe. Drop additional pieces of the hotdog as you walk away from your pooch. Drop about every eight to ten feet for twenty feet. Lay your dog’s toy or another play item on the last of the hotdogs you drop.
You want your pooch to find something at the end of the rainbow. Then drop another little piece of hotdog on the toy.
3. Ask for the treat
Release your dog and encourage them to find the smell. Say the words “find it.”
When he starts to follow the trail give them praise.
Your dog should know what to do. Let him figure it out. Don’t lead him.
Your dog will be tracking using a combination of the hotdog’s scents, the crushed grass scent, and your scent.
4. Increase the trail
Once your dog has succeeded, try to lengthen the track. But keep the training sessions short. Make it a fun thing to do.
Related Questions
How far can a dog smell underground?
Trained cadaver dogs have been known to detect the odor of human remains from deep under the ground. They can also detect smells underwater without getting wet. A properly trained dog can detect as far as fifteen or more feet underground. Underwater is even more impressive. Without getting wet a trained dog can smell up to eighty feet underwater.
How far can a Beagle smell?
Beagles are one of the top dogs when it comes to their ability to sniff out a scent and track it. How may scent rectors do they have? 220 million. That’s 45 times the number of receptors a human has. With such a high volume of scent receptors, they can smell far…up to 60 square meters or 2.3 square miles.
Here’s another interesting statistic: an un-neutered male can get a whiff of a female in heat from two to three miles away.
How far can a dog pick up a scent?
In terms of how far away can a dog pick up a scent, the answer is as far as 40 feet underground.
In Conclusion
Dogs are naturally born with this razor-sharp sense, and you, as their owner, can help them develop it if you choose to. This sense is built into them for their own tracking skills – and it has come in handy for many human needs, too.