Police dogs have become a vital part of the police force. They are well trained, obedient dogs that, unlike humans, do not fear the daily challenges that arise on the job. Police units throughout the world use K-9 units. They are employed by most local police forces and by many governmental agencies. Police dogs can search 400 to 500 packages in a half an hour. They can search a car every minute. This speed saves time, when a human searcher could only do about one car every twenty minutes. Also, according to Canada Customs, in one year, 1993, the dogs searched 80,000 cars, 11 million packages and 6 million units of cargo. From this, they found 58,000 pounds of marijuana, 3,027 pounds of hashish, 18 pounds of cocaine, 29 pounds of heroin, 5 pounds of opium and 4.3 million dosage units of illegal prescription-type drugs. The combined value of all these drugs in 1993 was $192.5 million dollars.
Throughout the years, dogs have been trained using natural and artificial scents; they continue to use this training by tracking people and substances, despite on the job hazards. As man evolved, he began to use dogs to hunt prey and search for food. However, as he became more civilized, he needed to use dogs for more than those three simple things. He needed dogs to perform certain and specialized tasks. This is how selective breeding began. Certain dogs were used to herd sheep and were common on a farm. These dogs became known as Shepherd dogs. The German Shepherd in particular, is a late breed of various breeds of Shepherd dogs in Germany.
Through selective breeding, they were adapted for the rough job they had, plus new ones. Their shaggy coat developed into a thick, dense, short coat. They are relatively tall, (22-26 inches) and have a medium sized head with a long nose. This large body helps it support more muscle mass, so German Shepherds are usually very powerful. They have extremely powerful jaws with strong teeth, and have a scissors type bite, so they grind and shred whatever they are chewing. German Shepherds are usually used as police dogs because they are natural born working dogs. They have been trained and bread to be used to work, so they are very easily trained and extremely loyal. They are restrained and will usually not attack suddenly, but they can fight well. They are judged by breeders as very smart and are considered to have great judgment.
Dogs have been used for police work for over 75 years and are used all over the world in such places as the North America, Europe, the Far East and Russia. New York City was the first city to use police dogs, but with little success and money running out, they abandoned the idea. Then later, in London, they were very successful. This was taken up by other nearby towns, and soon spread to many large cities. Early ways in which canine units were used were crude and probably explain the reason they were not successful at first. They would use the dogs as a crime deterrent, releasing them into the city after curfew, free to attack anything they wanted. Now, both dogs and partner go through very specialized and rigorous training. Current use of dogs on police forces is divided into five categories: Search, attack and capture, detection of explosives, detection of narcotics and a deterrent to crime.
The search portion is used to find lost people, people trapped in wreckage or other things, and to find lost items. Attack and capture is used for exactly what it sounds like. The dogs are used in pursuit of a criminal on the run and hold him until the dog’s partner can arrest him. Detection of explosives and narcotics is used to find explosive substances and drugs, usually ones that are hidden. Deterring crime is a specialized field. Basically, the dog and partner patrol a certain area. People have a natural fear of large dogs. Criminals are a lot less likely to attack a person or police officer if there is a trained German Shepherd nearby that will attack on command.
Although dogs are usually very easily trained, it is hard to train them to a certain scent. The reason it is hard is not because the dogs can’t recognize the scent, or they can’t learn to identify it, but because trainers need actual scented items to train the dogs. For a dead body, the trainer needs actual items the body was in contact with while it was rotting. For drugs, the trainer needs to fill out a stack of paperwork to show that he is only going to use it for the training. If the dog happens to inhale any of the drug while he is sniffing it out, it usually results in the death of the dog.
Trainers tried to make substitute scents for drugs. For heroin, they used powdered milk, vinegar and quinine. For corpses, they used anything and everything, from road kill to their own blood. These substitutes almost never worked. This was the reason why a group of chemists at Sigma Chemical in St. Louis developed pseudoscents. These are chemical replicas of the real scent. The goal of these chemicals is to smell so much like the real thing that they can not be distinguished. If these pseudoscents can accomplish that goal, then the trainers will not need to use the real thing anymore, which will eliminate almost all of the hazards of training.
The way a dog’s nose functions is an important part of understanding why they are so important to the police force. In a human nose, the olfactory cells (the cells that pick up scents), are high up in the nose and are all in an area less than one square inch. Most dogs, take the beagle’s nose (a dog that is often used in search units), is drawn out, and their cells are six times as long. Also the cells are rolled up in a scroll shape inside the nose. These scrolls increase the surface area which the scents can hit and be detected.
Each cell, on both dog and human, has cilia, which are tiny hair-like extensions of the cell. These can pick up more, thus increasing the surface area. In humans, the scrolls are equal to around 3 square centimeters. In a bloodhound (another dog often used on search teams), they have a heavy nose with 150 square centimeters of membrane. In both dogs and human, they become accustomed to a scent quickly. When we become accustomed to the scent, unless it is really bad, we won’t smell it anymore. This is because the cells have stopped sending impulses to the brain, and the cells won’t detect anything unless the smell gets stronger. In humans, as part of being more intelligent, we have developed a mechanism to suppress the recognition of an odour.
However, dogs don’t have this mechanism. If they did have it, then it would be a huge handicap when it’s hunting. Also becoming used to a scent would be a handicap, but they can, in a sense, revive the cells by taking in a breath of fresh air. In humans we use our diaphragm to sniff, but dogs, and most other mammals, use their nostrils and the muscles in their nose to sniff. This allows them to sniff a lot faster, letting them take in more of the scent. One dog in particular has another special adaptation for trailing things. Scientists are not quite sure how, but bloodhounds seem to be able to pick up certain scents in specific parts of their nose. Every scent fits into the cell like a lock and key.
The way dogs are able to track human scent is that our skin cells are constantly flaking off. What happens is that the air around a person’s body is being heated to 98.6. When the hot air rises, it brings up bits of skin and bacteria that live on the skin. This is known as raft. Raft is invisible, but is always coming off peoples’ skin. They spray up and fall around our feet. The human body has 60 trillion skin cells, and about 50 million flake off a day. We also produce 30 to 50 ounces of sweat a day. The sweat and cells have no scent on their own though. The scent comes from the bacteria that live on the skin. There are million of bacteria per square inch, and when they break down lipids in the skin, they release a waste that can easily be picked up by a dog. This is why diet and bathing affect the scent.
Some families may have a common genetic scent, or be similar in scent by the fact that they all use the same soap or hand lotion. The adaptation of the blood hound having each scent fit in to it’s own cell makes it possible for a bloodhound to be able to determine between each family member’s scent. Tracking a scent in a field with no wind and enough time for the bacteria to react would provide the perfect setting to follow a scent. Most often the tracking is in the city though, where there are the rafts of the other people who have walked by. That’s why it’s important for a dog to be able to distinguish between different people’s scents. Wind can have a big effect on raft, which is blown around by a slight breeze. To understand the effect, if smoke blows in the wind, it flies to one direction. It is the dog and the handler’s job to be able to understand the way the wind blows and not be distracted by a blown raft.
When wind hits a building, it swirls of backwards and to the sides, so if the scent is blown against a building, then it could end up going in the opposite direction the wind is blowing and off to the side. A dog will follow the blown scent, depending on how far it blew. So even if a dog appears to be going in a random direction, he is actually following the scent that was blown over. There are also air currents in a building. They are usually more confusing because even though the person is in the other room, the dog smells him in the room next door because his scent is blowing through a crack in the wall. Around air conditioners it is also tough very to figure out because the vents blow the scent all around. Chemicals can also affect a dog’s sense of smell, but usually just for a short period of time.
This is why people try to cover up food or drugs by putting them in perfume soaked clothes, or hiding them in a shoe. A scent can not be masked. The only way to affect a dog’s sense of smell is to deaden it. This is when a scent washes out the cells in the nose, and everything smells like that for a short period of time. German scientists did a study on the effects of pollution on scent. From zero to five feet up, the pollution was the thickest. A German Shepherd’s nose is even with the tailpipe of a regular sized car. This can affect a dog’s sense of smell. This is why a handler must be aware of chemicals and pollution. If there are a lot of either of these things, that can deaden a dog’s sense of smell. Sometimes in conditions like that the job is better done by a person.
A dog can smell about 10% to 100% better than a human. 100% if the scent is really subtle and 10% if it is a very strong scent. An example of this would be that a person can smell a bottle of perfume almost as well as a dog. The dog however, can smell something hiding in a bush that he just passed, whereas a person would not be able to. Pigment of the skin also affects a dog’s sense of smell. Dark dogs have been recorded as being able to smell much better than a lighter dog. This is the reason why white dogs are not used in K-9 units.
A serious hazard for the police dogs is the people who get the drugs seized from them. Drug lords are not happy when they lose drugs and money. In eleven months, two dogs who patrol the Mexican border have seized $128 million in cocaine and other drugs. Because of this huge loss, drug kingpins have put a $30,000 contract on the lives of the two dogs. Because of this, the K-9 unit down there was forced to give more protection to the dogs and to hire more dogs.
Trained by law enforcement officials using natural and artificial scents, dogs have been useful for years in tracking people and substances, despite the hazards that arise on the job. Police dogs seize tons of drugs and contaminated food every year all over the country. They prevent crops from being destroyed by foreign pests and prevents some drugs from coming into the community. Police dogs also help find lost family members, whether they are lost in the forest or in a collapsed building. Police dogs help protect the lives and well being of the citizens they are in charge of protecting, and we should recognize and be appreciative of that fact.
“The Border’s Nosy Narcs.” Time 21 March 1988: 33.
“We Shed 50 Million Cells a Day; They Make Good Scents To a Hound.” Smithsonian Jan. 1986: 64-72.
“Just Say No, Rover.” Time 12 Nov. 1990: 43.
http://www.best.com/~policek9/k9home/theory.html: 1-4. Newlon, Clarke.