Of all the senses, the dog has the best developed sense of smell. Scent is undoubtedly the most important of the sensations practically used by a dog; it is the main sense by which it learns about the world and is guided in life.

Unlike humans, a dog's brain is wired to process olfactory rather than visual information, which makes it extremely difficult for us to understand. Try to imagine a world created not from images, but from millions of smells of varying intensity!

The dog's sense of smell is so superior to humans that we can hardly even try to appreciate its extraordinary ability to distinguish thousands of different odors, and not only to clearly distinguish them, but also to do this at extremely low concentrations.

Puppies are born blind and deaf, but with an excellent sense of smell, which in the first days helps them navigate the world around them. In both humans and dogs, the olfactory center of the brain is responsible for the perception and processing of information about the received smell coming from the olfactory receptor cells.

Unlike humans, a dog actively collects odor information, using the special functions of the olfactory organs.

A dog’s brain is 10 times smaller in size than a human’s, while the part of the brain responsible for smell is 40 times larger than the olfactory lobe of our brain, and the ability to identify odors is 1000-10000 times higher.

First, dogs have movable nostrils, which helps them determine the direction of a scent. Secondly, they know how to sniff - this is a special function that is very different from normal breathing. Sniffing is a surprising disruption of the normal respiratory process, consisting of 1-3 consecutive repetitions of respiratory movements, each of which contains from 3 to 7 intense intakes of air. The most sensitive part of a dog's nose, the septal organ, is likely responsible for initiating this process.

The thickness of the dog’s olfactory epithelium is 0.1 mm, and in humans it is only 0.006 mm; The dog's olfactory bulbs are also much larger; total weight equal to approximately 60 g, which is 4 times more than that of a person.

During normal breathing, air flows freely through the nasal passages and down to the lungs. When sniffing, the air drawn in with odor molecules passes through bone structures nasal cavity, called the subethmoidal (subethmoidal) protrusion (humans do not have them), and then falls on the inner surface of the nasal membranes.

The sublatticed projection blocks inhaled air, preventing it from being “washed out” during exhalation, allowing odor-carrying molecules to accumulate. An average-sized dog produces approximately 450 ml of mucus per day.

Everyone knows that a dog's nose is usually moist and cool. Moisture on the nose is produced by many mucous glands located in the nasal cavity. Nasal mucus is needed not only to cool the nose, its main function is to capture, dissolve and accumulate odor molecules from the air and promote the “odor solution” to the receptor cells densely packed on the olfactory epithelium of the inner surface of the nose.

For normal operation this transport system required a large number of mucus. If there is not enough mucus produced, the dog licks the nose; if there is too much mucus, the “extra” mucus flows out from the lips, forming hanging “drool” in some bristly breeds.

An extremely complex system of bends of the maxillonasal turbine bones, which look like labyrinthine shells with thin bone scrolls covered with olfactory epithelium containing receptor cells and nerve endings, is designed to create a flow of air that brings odors to the area of ​​the olfactory receptors, where chemical Signals from odors are converted into electrical signals and transmitted to the olfactory center of the brain.

In humans, the total area of ​​the olfactory cells is about 7 cm2 (about the area of ​​a postage stamp). In a dog, this area can occupy up to 390 square cm (a sheet of writing paper). The size of the area varies depending on the size and length of the dog's nose: dogs with a wide, long muzzle have more olfactory receptors and therefore a higher ability to identify odors than breeds with a narrow, short muzzle.

Nature has provided something else to ensure the dog's exceptional sense of smell. Distinction and recognition of odors occurs not only in the nasal region. In the dog's mouth, on the palate, immediately behind the incisors, there is a special formation - the so-called vomeronasal, or vomeronasal organ. It is a small oblong tubercle lined with receptor cells and communicating with both the mouth and nose.

This is the biggest mystery of the dog's nose; its true purpose is still unknown. It is believed that this organ performs one of the functions in the emotional behavior of dogs by detecting pheromones - odorous chemicals secreted by animals and, as a rule, poorly or not perceived by humans.

This odor information is transmitted by the vomeronasal organ directly to the limbic system - the oldest center of the brain, which evolved long before the centers of vision and hearing, and is responsible for emotions, spatial and factual memory, as well as for all basic types of animal behavior: feeding, sexual, territorial, social .

The dachshund's nose has approximately 125 million odor receptors, the fox terrier's - 145 million, German Shepherd- 225 million. Tracking hounds have noses designed to accommodate as many scent receptors as possible in the space allotted to them - even if the dog itself is small. The extremely scent-oriented Beagle, who weighs approximately 14 kg and stands no more than 38 cm tall, has the same number of olfactory receptors - 225 million - as the German Shepherd, which is twice the Beagle's size and weight!

Well, the champion of scent among dogs - the bloodhound - has 300 million receptors. The human nose boasts only 5 million receptors, which is about 2% of the number of biglins.

Pheromones serve to transmit “personal” information about an animal to other individuals (usually of the same species). By applying the scent of its body to surrounding objects (by rubbing itself on the ground or tree trunks or leaving scent marks of urine and feces) or by reading other people's marks, the dog notifies or receives information about the gender, age, health, sexual state, even emotional status of other members of the group. For example, aggression, fear, excitement, and the degree of saturation are accompanied in animals and humans by a change in the usual body odor.

When frightened and aggressive, a dog often secretes the contents of the odorous anal glands and thus signals its condition by smell. When meeting, dogs carefully sniff each other, first examining with their noses those places where there are scent glands. Even dogs living in the same house constantly sniff each other to get the latest news about the well-being and condition of the household.

By catching the smell of pheromones, the dog can prepare for social contacts with fellow tribesmen and determine the nature of further relationships and the line of behavior: peaceful or hostile.

The dog is able to sense and identify such a faint odor that even the most sensitive devices cannot register. It's hard for humans to imagine how much more sensitive dogs' noses are to certain smells. They are especially finely tuned to the smells of animal origin, which is understandable, taking into account that the dog is a predator, and initially its nose served it for hunting.

For example, dogs can smell a drop of blood in five liters of water. Dogs can smell butyric acid, the odorous component of human sweat, at concentrations a million times below our threshold of sensitivity. Dogs can follow human tracks even if those tracks were left many hours ago or covered with strong-smelling substances, even if the person is wearing rubber boots or riding a bicycle. A dog can smell a smell of strong physiological significance (for example, hunting dogs - the smell of game) at a distance of 1 km.

The dog is able to remember smells and associate its olfactory sensations with a variety of past experiences. The memory for smells lasts throughout the dog's life.

A dog differs from a human not only in its acute sense of smell, but also in its amazing ability to process odor information.

A dog’s sense of smell is analytical, it is able to perceive and simultaneously subdivide many different odors, as if “stratifying” them - just as we are able to distinguish individual objects and details in the general visual picture of the world around us. Imagine walking into a kitchen where a meat stew is being prepared.

You will definitely smell the meat and spices. Your dog will not only distinguish all the “layers” of this “smell mixture” - potatoes, carrots, tomatoes, onions, beans and each spice separately, but will also easily identify the smells of pork, beef, lamb, rabbit, which, in our opinion, they smell almost the same.

The dog's ability to sense and identify odors, as well as navigate using a sense of smell that is especially finely tuned to biological odors and pheromones, has given humans the opportunity to use them for a variety of purposes - from hunting game to searching for criminals or searching and rescuing people under the rubble of buildings or in snow avalanches, where a dog finds a person under many meters of stone or snow. Among the most famous service “professions” of dogs is the search for drugs, weapons, explosives and flammable substances, gas leaks, and prohibited food products.

For a dog, footprints are as material as photographs that capture moments of the past are for us. By the scent of the trail, the dog can determine who exactly passed, in what direction and for how long ago.

Search abilities manifest themselves differently in dogs of different breeds. Some breeds - such as beagles and bloodhounds - are good at picking up tracks on the ground (i.e. using their lower senses). Dogs of these breeds usually slowly and carefully sniff the ground along which the track was laid, follow the chain of tracks left, literally moving from one track to another. This is the so-called “tracking” (from the English track - to follow the trail).

A dog working in this way best takes a relatively fresh trail, on which it easily picks up the smallest particles of odor emitted by the pursued through the pores of its body and left by it along its path; in addition, the smells of trampled grass and earth most likely help it keep the trail. However, more often the dog uses a different method: it does not follow the tracks itself, but follows the smell of microscopic particles of organic substances (skin epithelium, hair, saliva, sweat), continuously “dropped” by a person or animal.

Since these particles, falling before settling on the ground, are picked up and carried in different directions by air currents, the dog can walk parallel to the track, sometimes at a considerable distance from it.

This method is called “trailing” (from the English trail - to reach behind, in the form of a cloud, a train). The already mentioned Bloodhounds are the best trailers in the world, they have an excellent memory for smells, and they can follow a scent all day long without the stimulation of “smell memory” - additional sniffing of an object belonging to the search object.

Studying the smell, the dog usually begins to energetically, deeply and quickly draw in air, flares its nostrils, lowers, or less often raises its muzzle. On the street, she often turns her body or head against the wind. Rapid lateral tilts of the head are also characteristic, allowing one to detect the slightest vibrations. air flow. Sometimes a dog, attracted by some smell, covers or completely closes its eyes. This means that she sensed something extremely pleasant or interesting for herself.

An alternative method of search work is by top instinct, i.e. by the smell left in the air. Dogs that take a scent in the air, in search of a scent dissolved in the air, run with their heads raised around the examined area, moving in different directions, spinning in place and ever expanding circles, and as soon as they catch the scent, they run straight towards its source.

This method is most successfully used in search and rescue operations, in disaster areas, especially during building collapses, when it is necessary to determine the presence of a person as quickly as possible, and not to follow exactly in his footsteps.

Generally, search and rescue teams prefer to work with German Shepherds, Collies, and Labrador Retrievers. They are trained to distinguish odors that are a “mixture” of the odors of many people of different ages and genders. There are dogs specially trained to search for dead bodies. They are able to detect bodies buried in the ground or under water.

A dog's great genetic design already has room for a remarkable olfactory system, but even this can be improved through breeding and training. Sensitivity to odors is partly inherited. An excellent example of enhancing innate abilities through selection is the beagle, basset and bloodhound. These breeds were bred specifically for hunting and are now recognized experts not only in identifying and distinguishing the smells of game and animals, but also in their special passion for searching and studying tracks, and hounds have no equal in their ability to follow the scent.

The “beagle crews” sniffing out prohibited agricultural products at American airports are an excellent example of the ability to develop the exceptional abilities of beagles through training. The training technique is brilliantly simple.

The training begins with citrus fruits, teaching the beagle to identify an orange by sitting down to eat sausages on command. First, the dog is taught to sit like a million other dogs in obedience training, using sausages as a food reinforcer. The odor of orange is then introduced and this odor replaces the audio command. Beagles are very curious by nature and love to explore everything with their nose. The instructor places an orange in a cardboard box and moves it around.

The beagle explores the box, intensively sniffing it, all the cracks and open areas of the box. After a period of sniffing, the trainer can be sure that the dog has remembered the smell of the orange. At this stage, the command “sit” is given. When the dog sits down, he is rewarded for following this command with a piece of sausage. This process is repeated several times, and there comes a time when the dog sniffs the box, and if he detects the smell of orange inside, he sits down.

Classic method.

Another profession that dogs have been trained to do is arson detection. Dogs are trained to detect the presence of flammable liquids (gasoline, solvents, etc.) that could be used to deliberately set fires. It has been established that a dog can smell flammable liquids even 18 days after a fire has been extinguished, while electronic detectors must be activated immediately to obtain reliable data, when the fire has not yet been completely extinguished and the building is dangerous to enter.

Most often, black Labradors are used on fires. In the USA, many people have their own Labradors. Insurance companies, about 50 dogs of this breed are on the staff of the Federal Bureau of Alcohol, Tobacco, Firearms and Explosives.

In Europe and the USA, dogs have long been used to inspect gas pipelines to find gas leaks. It only takes 1-2 days for a dog trained in any type of search work to learn to smell buried objects treated with butyl mercaptan, a compound used to “odorize” odorless natural gas. With amazing accuracy, the dog is able to smell it at a depth of 12 meters - where the sensors of devices for detecting gas leaks are powerless!

The list of specializations of search dogs goes on. Four-legged experts show excellent results in detecting houses infested with termites - 95% versus 50% reported by devices. Dogs can easily find toxic mold that is dangerous to human health in residential areas. IN last years Research is underway to study the ability of dogs to detect cancer cells in the human body. The results of the experiments are very encouraging.

For many years now, all passengers arriving at US international airports have been greeted by a team of cute, cheerful beagles in green and blue vests. They walk busily among travelers and poke their noses everywhere, happily accepting the attention of others and wagging their tails affably. In fact, they are on duty - they are interested in the contents of the pockets, bags and suitcases of the arrivals.

This is a beagle brigade - a special detachment of beagles and inspectors-guides created within the structure of the Veterinary and Phytosanitary Inspection Service (APHIS) of the US Department of Agriculture to inspect baggage at international airports. The brigade searches for and confiscates agricultural products prohibited for import into the country.

Plants, fruits, vegetables, meat and other animal products imported by ordinary tourists without complying with veterinary control regulations (i.e., simply undeclared) can carry pathogens or plant pests that can cause significant damage to US agriculture. According to the Department, about 75,000 seizures of prohibited products are carried out annually in the country thanks to beagle teams.

APHIS works with U.S. Immigration and Customs Enforcement and the U.S. Public Health Service at every port of entry across the country, including land border crossings, international postal terminals, seaports and airports. Beagle teams typically patrol baggage claim areas at international airports. These cheerful, cute dogs in green vests are the first to greet passengers stepping off the plane.

The airport baggage screening program began in 1984 at Los Angeles International Airport. And already in 2004, more than 60 beagle teams worked at 21 airports in the country. All four-legged members of the team were either donated by private owners and breeders, or adopted from shelters. The dogs were tested for traits such as friendliness and intelligence. Those who were not selected for service ended up in “foster” families—not a single dog was returned to the shelters.

Why beagles? After all, service breeds are much more common in the role of “bloodhounds”: shepherd dogs, Rottweilers...

Firstly, because they are simply charming, sociable and friendly, and due to their small size they do not evoke feelings of fear or mistrust in people. Secondly, beagles are very interested in food and other animals - especially their smells. Originally bred to hunt rabbits, beagles have an exceptional sense of smell, capable of detecting odors so faint that they are practically inaccessible to measuring instruments. It was these qualities that influenced the decision to choose this breed for baggage screening at airports.

It turns out that beagles make not only wonderful pets, but also excellent federal agents!

They help inspectors make the inspection process not only immeasurably faster and more accurate, but also objective, regardless of the passenger’s identity. The fact is that very often people violate the rules for importing plants, fruits or meat products not intentionally, but out of ignorance, they simply do not understand why a tulip bulb brought from abroad, or a lemon, or a piece of cheese, or a special a type of smoked ham.

And if they start to get angry and protest against a body search or a search of their luggage, it is very convenient for the inspector to refer to the cute beagle: “I beg your pardon, sir, I am only doing what the dog shows me!”

In order to become a member of the brigade, a beagle must have some other qualities. First of all, the beagle must be extremely friendly to people - adults and children, because this is the very contingent with which he will have to work. And one more thing: the beagle must be very highly motivated by food, since it works for food (which, in principle, is expected, because beagles are known for their omnivores and insatiable appetite!).

Before starting work, beagles undergo 10 to 13 weeks of training, most often at a canine training center in El Paso, Texas. In order to select one promising candidate for study, you have to look at from 5 to 15 beagles - usually between the ages of 1 and 3 years and not necessarily purebred.

They begin training by recognizing 5 key smells: mango, apple, citrus, pork and beef. The dog is rewarded with a treat each time it discovers an item with the desired scent hidden in a cardboard box, and sits and waits quietly next to it.

Gradually, as the skill is consolidated, the target is hidden in suitcases, first soft, and then hard, and all sorts of objects are added, usually packed in luggage by tourists. Then other products are added, often carried by passengers - this is how the beagle is taught not to pay attention to chocolates, cookies and other unrelated items. The Beagle is trained to be so selective that it can distinguish the smell of fresh mango from mango shampoo.

Beagles are good students. Usually, after 2-3 days of intense training, liberally flavored with numerous pieces of treats as a reward, the dog is able to recognize the desired smell, and the rest of the course is spent honing the skill and learning to find the smell everywhere.

Exactly everywhere - in suitcases with things, backpacks and wallets, bicycle tires, car trunks, bottles of baby food, cowboy hats and vases with a second bottom... Even if the item is hidden in a hermetically sealed container, you can’t fool a beagle’s nose!

After a few weeks of training, the dogs are assigned to inspectors who have also completed their training. Couples need to “work together”, and sometimes this takes quite a long time. After just 6 months of work, a beagle is able to detect prohibited products in 80% of cases; by the end of the second year, trained beagles are not mistaken in 90% of cases. Beagles' odor recognition abilities are extremely high; some can recognize up to 50 different odors.

It is interesting that beagles are usually not taught to detect wild or exotic animals, but their natural hunting instincts do not sleep, and the beagle sometimes suddenly alerts the inspector about unusual contraband. There is a well-known story about Shelby, the super beagle, who smelled live snails in sealed plastic containers hidden among things in a suitcase.

After training in the controlled, sterile environment of training classes, the beagle-inspector pair undergoes the final stage of training "in combat" - at the airport, where they must work among the noise and hubbub of thousands of rushing people and many distractions.

The Beagle sniffs the luggage of all passengers without exception, regardless of whether they have declared anything or not. If a beagle smells a contraband product, he sits down next to the “guilty” luggage and waits for the inspector to approach, who will definitely treat him to something tasty! The teams train at the airport for a month, then take a final exam and, if successful, earn the right to work at one of the country's international airports.

Most beagles' careers in the team last from 6 to 10 years, and after "retirement" the handlers with whom they worked in pairs for all these years usually take them into their homes. In other cases, “foster parents” are found for beagles.

This is probably the best activity of all for a non-hunter beagle. Still would! To do something really useful, and at the same time get a lot of pleasure: every day to sniff everywhere you want and as much as you want, to look for food, to swim in the sea of ​​attention from others and to receive a tasty treat for every find - what else can a beagle dream of?

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Dogs perceive our world differently, and not because they are dogs, but because they feel and touch it better than we do...

Today we will talk about how and with the help of what senses dogs perceive the world around them. We really hope that this information will help us get to know our pets better, and many dog ​​habits will become clear to us. So, features of your dog’s sense of smell, sight, hearing, touch and taste...

Dog scent

It is no coincidence that when people talk about a keen sense of smell, they think of a dog, because dogs have the best developed sense of smell, and this is not by chance. A dog's life is filled with various smells that are constantly changing, intersecting and layering one on top of another, and in order not to get confused in such diversity, the dog needs a very subtle sense of smell, which will allow it to differentiate different smells and separate such a cocktail of smells into individual ingredients. So, for example, a dog can easily smell one single drop of blood in five liters of water, and differentiate which animal a piece of meat belongs to - a pig, a rabbit or a sheep, while it is simply impossible for a person to distinguish by smell whether such meat belongs to a specific type of animal. Well, as for human smells, here dogs have no equal at all - following the scent, distinguishing twins by the smell alone - all this is within the power of our dogs. Bloodhound dogs, of course, have a special, delicate sense of smell; thanks to special training, nothing is impossible for these animals; they can follow a person’s trail, but only when this trail is interrupted – the dog is powerless here. It is noteworthy that such a subtle sense of smell is facilitated not only by the presence of internal sensors, but also by the external part of the dog’s nose. So,

at healthy dog, in order for her to perceive odors, her nose must always be wet, this allows her to absorb odors from the air that she inhales. When an animal gets sick and its nose becomes dry, the ability to distinguish odors also decreases.

As you know, everything is learned by comparison. So, in order to understand how powerful a sense of smell our dogs have, it is enough to know such a fact as the fact that

in humans, the total area of ​​the cells responsible for the sense of smell is about four square centimeters, while in a German shepherd the same figure is an area of ​​one hundred and fifty square centimeters!!!

Just imagine the difference. Dogs actually sense the world around them differently than we do. Also, in humans the number of olfactory cells is five million, while in a basset dog there are one hundred and twenty-five million, and in fox terriers there are one hundred and fifty million, and in a German shepherd there are as many as two hundred million olfactory cells!!! It is no coincidence that scientists claim that a dog senses odors forty times more acutely than a person, and some experts are even confident that in fact, this figure, which determines the degree of sensitivity, is much higher.
When it comes to special scent notes, dogs are best able to smell the fatty acids that are part of the diet of carnivores.
Is it possible to turn a dog into a real bloodhound? Of course, it is possible if you train the animal and work with it according to a special program. So, for example, if you do not feed your hunting dog meat before the hunt, its sense of smell will become sharper, and it will be able to pick up even the oldest trace, which is why hunters prefer to put the animal on a diet before the hunt, so it will be better able to pick up various odors.

Dog hearing

Our dogs also have a very developed way of perceiving the world around them - they hear very well, so well that they pick up ultrasonic waves that the human ear is not able to perceive due to the high frequencies of such vibrations. So, during the war, soldiers very often used this ability of dogs in order to transmit commands to them at a distance that the enemy could not hear. You won't believe it, but

Our Burans and Vyugas are able to hear sound whose source is located at a distance of 24 meters, while for a person such a sound limit is only 4 meters...

But that's not all. A dog can distinguish sounds from each other, which at first glance are no different - if he could speak, he would definitely tell us that different engines of the same car brand sound differently...

Dog vision

Despite the fact that there is an opinion that dogs see the world in black and white and do not know colors, in fact dogs have very good vision, and at night they see much better than you and me. So, for example, representatives of the German Shepherd breed have a visual field of as much as 180 degrees, and they are able to see the gestures of their owner at a distance of several hundred meters!

Dogs' sense of touch

Unfortunately, this area of ​​perception in dogs has been little studied, but even the small amount of information that we have on this matter allows us to draw conclusions that temperature, tactile and pain stimuli are perceived differently by the skin of dogs and their mucous surfaces. So, a dog is able to feel the slightest breath of breeze that touches its fur, which is why, when the air temperature drops, dogs “fluff” their coat, thereby protecting themselves from hypothermia. But representatives of northern dog breeds can even sleep in the snow in severe frost, and not experience any discomfort.

The modern doctrine of smell and odors, which contains still unresolved questions, belongs to the most complex areas of science. Despite numerous studies, this area of ​​knowledge is still replete with “blank spots”. The information presented below, so necessary for working with PSS dogs, is only the most necessary in an extremely abbreviated form.

Smells are the main source of information a dog receives from external environment throughout life. She develops conditioned reflexes to smell more quickly and easily than to any other stimulus and is more persistent.

Characteristic features of the olfactory system of dogs, like other mammals, are, in addition to high absolute sensitivity to certain substances, high speed of highly accurate analysis, identification of individual components in complex mixtures, as well as the ability to memorize mixtures of many components and their subsequent recognition even with partial changes in composition . Moreover, the dog's olfactory system can detect complex mixtures of odors and recognize them as a single stimulus. This unique property does not require the separation of mixtures into components, which is necessary for analyzes performed in the laboratory. The ability of the olfactory system to make subtle distinctions between mixtures containing the same components but in different proportions makes it especially valuable. information system.

The olfactory system of mammals has high sensitivity To a large number substances. According to the definition of dog handler and odorologist K. Sulimov, “the olfactory act can be considered as a process of recoding information from odorous substances into nerve impulses, as a result of the analysis of which the individual receives necessary information, followed by a specific behavioral response under certain conditions and internal states, including individual experience."

Smell and sense of smell are similar concepts, but not identical. The sense of smell is the physiological ability of an animal organism to perceive and distinguish odors in general. Smell in a broad sense is the ability of an animal to detect any source of an odor of interest through its senses, mainly smell.

In dog breeding, scent is understood as the dog’s ability to detect a very specific source of the desired smell - a person, game, mineral, etc. Hunters understand the concept of scent not only as olfactory abilities, but also as hearing and vision, which dogs always use in combination, which significantly helps them at work.

Dogs “smell with their ears” due to a certain physical and physiological pattern. For example, on a snow surface, sound coming from a victim from a snowbank experiences complete internal reflection, except for a small conical zone directly above the sound source. The sounds emitted by the victim have a wavelength significantly shorter than a person’s height. Therefore, only a dog whose ears are much closer to the surface of the snow can hear them. The passage of rescuers' voices deep into the rubble is also difficult. For this reason, with good audibility of footsteps, probes - everything that moves directly through the snow, the victim in the rubble will not hear the voices of people, but will hear the barking of a dog.

Dogs hear better than humans due to their increased sensitivity to high-frequency sounds. Upper limit The auditory range in humans is about 20 thousand Hz, in a dog - up to 40 thousand Hz. Since dogs hear higher-frequency sounds, they respond to the sounds of technical devices: a remote TV channel switch, a smoke indicator, an electronic flea collar, and others.

On average, a person can easily distinguish several thousand odors, and an experienced specialist can distinguish more than ten thousand. Smell is characterized by a dog’s ability to smell well only the sources of smell needed in its service. In other words, not every good sense of smell is a good sense of smell, but there cannot be a good sense of smell without a good sense of smell.

It is important for the trainer and guide to understand and “feel” how complex the process is in the dog’s body in order to detect the desired smell. Only then will the handler become sensitive and attentive to the dog during the search for the victim, and will he understand why, thanks to “control,” the search is sometimes unsuccessful. Then it will be clear why you can’t pull or tug on the leash even outside of work, on a walk, when the dog sniffs, smells, and, even more so, sniffs something. Her brain centers, including the ERD, work only when receiving olfactory information; without this, they are inactive and weaken, not to mention the weakening of the sense itself. What is important is not the theory of the mechanism for taking odors, what is important is the practice of never interfering with the work of the dog’s olfactory apparatus.

Flair-smell - concepts and their corresponding dictionary meanings are not identical and are not synonymous when assessing the performance of dogs. In colloquial language, “smell”, in addition to the subject’s olfactory abilities, is understood as the dexterity of finding something needed, his resourcefulness, and ingenuity.

Many hunters use this word to mean the dog's "sense." However, “a dog’s sense of smell” is a broader and more complex concept. It includes a whole range of individual behavioral actions, such as quickly assessing and unraveling a complex situation, anticipating its changes, dexterity in achieving a goal, and others. Using the concept of “smell” in classes and rescue work, as a more specific, clear one, one should not ignore the “smell”, which expands the characteristics of a dog in its work and everyday behavior.

From the behavior of animals, both wild and domestic, it follows that depending on the task set by life, the situation, the level of development of the receptors involved and the ERD, the target actions of the same animal will vary significantly. Thus, while only walking around its territory (yard, forest), a dog or wolf in a calm state mainly uses sense of smell(nose). But having caught the smell of a “stranger” (person, animal), it automatically turns on flair(nose + ears + eyes). If, when walking around the territory, the “stranger” is not detected, then certain centers of the central nervous system are additionally excited, and all reserves are included in the work - smell, electric propulsion.

A beginning dog searches using only its sense of smell (it reacts to all odors outside the area, etc.), its sense of smell is not yet developed. After completing a course of PSS classes, she begins to work with her senses (of course, her sense of smell has not disappeared - she perceives all smells, but ignores those she doesn’t need). After 2 years of work, she uses tricks and cunning to find the source of the smell (IS), that is, she has a sense of smell, which is only possible with the inclusion of electric propulsion in her work.

Smell is an elementary rational activity

Receiving olfactory information and the possibility of motor activity are necessary conditions for the full functioning of dogs, like other animals. For this reason, the manifestation of ERD in them is associated precisely with these physiological functions. The manifestation of ERD in all animals occurs in difficult, extreme situations, when instinctive behavior and individual learning do not ensure the implementation of new actions in their lives, in new conditions. environment. An extreme situation is characterized by altered afferentation (impulses to the central nervous system from the sensory organs) and the presence of a risk factor.

Sense of Sense

There is not a single type of sensation that cannot be developed through training. It is systematic, regular training in finding the source of the desired smell that is the best remedy so that the dog has a well-developed, acute sense of smell. The ability to detect the desired odor in trained dogs is several times greater than in untrained dogs.

The acuity of the sense of smell is determined by the threshold concentration of the captured odor and the ability to process it in such a way as to accurately differentiate the desired odor from others and determine its location. Therefore, the sharpness of a dog’s sense of smell depends not only on the sensitivity of the olfactory cells, but also on the analysis of odor information in the processing parts of the brain.

In dogs, the first place in terms of development is the sense of smell, the second is hearing, and the third is vision. It is no coincidence that the sense of smell is the first of the distant analyzers to begin and the last to finish functioning in her life. Despite this, a complex stimulus formed from visual and olfactory components is perceived nervous system dogs in a fused form as a single synthetic stimulus, and not the sum of its components. Integration of olfactory and visual analyzers determined by the close functional connection between the visual and olfactory systems.

A temporary exacerbation of a dog's sense of smell can be caused by certain artificial techniques. The stimulation method consists of playing and running with the dog a few minutes before the search - increasing its general nervous activity. Before giving the command “Search!” for several seconds they scratch her fur in an exciting manner and pronounce her name with increasing intonation. Just before the launch, the dog’s nasal openings are covered with a hand, which forces it to take as deep a breath as possible after removing the hand. These techniques often help her to catch the smell of even a subthreshold concentration from the spot.

Predominant behavior

In addition to sense, a dog’s detection of the victim’s PSS involves a whole complex of sensory systems. In addition to rational activity, an equally important role is played by the dog’s search ability, its motor system based on the predominant indicative search behavior. Starting from puppyhood, it is preceded by an indicative reaction, which is later improved and transformed through education, training and training. In the domestic literature, due to the lack of an exact concept and term, there are also other similar names “indicative-exploratory”, “olfactory-search”, etc. Among various types behavior manifested during external and internal stimulation of the central nervous system, more often than not, one in a dog is more pronounced and is predominant.

Approximate type of behavior to new or unusually strong stimuli manifests itself in the form of cognitive reflexes by sniffing, listening, examining, licking, digging. In the process of learning with the accumulation of conditioned reflexes, the orienting reaction manifests itself more moderately and, combining with them, provides the dog with orientation in a new life environment. This reaction, depending on the conditions of learning and the dog’s life, is modified and replaced by a new one - most often indicative-search, defensive and others.

The timing and degree of manifestation of the initial orientation reflex and its transition to mature, for example, orientation-search behavior depends on the degree of anatomical and physiological maturity of the corresponding organs. The indicative reaction appears in puppies from the first day of life, first to odor and taste stimuli. To olfactory reactions, the indicative reaction is immediately stable and clearly expressed, which is of vital importance.

Following the development of olfactory, gustatory and tactile analyzers, there is a gradual maturation and inclusion of others - auditory and visual. These remote analyzers perceive and process distant signals, thereby expanding and complicating the puppy's connections with the environment. His free movement around the area and the development of the motor system is a new stage in life. The capture of odor and all other stimuli is closely connected and intertwined with motor reactions, forming complex search behavior.

Constricted by the “apartment and leash,” the puppy’s richest innate qualities do not develop, but are suppressed and deaf. For this reason, it is more difficult to make a PSS dog from a puppy with the best “show” pedigrees, raised up to one year of age in a city apartment, than from a homeless mongrel, in whom all these innate qualities were not suppressed, but developed in natural conditions life.

Search by “upper instinct”
Search by “bottom instinct”

Approximate search(OP) behavior provides animals with natural conditions to find prey, food, water, etc. In the process of an individual’s life activity and learning, this reaction is determined by many conditioned reflexes and forms complexes with other behavioral reactions. The work of service and hunting dogs with “upper and lower” senses, their combination is entirely carried out on an indicative search reaction. For dogs of all services, this reaction is of paramount importance.

Based on the OP, behavior such as a “sense of direction” develops - the dog’s finding its home or rescue station hundreds of kilometers away; “sense of danger” - the presence of the dog’s enemies, dangerous places on the terrain, etc. With training, training and constant work of the OP, behavior moves to a higher level - search and survey.

Although this reaction is potentially present in many dogs, in some it may be mild and not predominant. Determining the degree of its severity is very important when purchasing dogs and choosing a method of training them.

Search and survey(BY) behavior It is characterized by the fact that if in OP the dog more or less quickly only searches for and finds an invisible victim, then in PO it precisely “examines” this area in the most careful way, where there may not be a victim. She does this not on command, but only with the slight promptings of her guide. During such an examination, the time spent is not taken into account. If there were no victims in the area, then the result of the work is no less important - the conductor signs the document: “There are no victims in the surveyed area.”

But it also happens that the smell of a subthreshold concentration, which is usually not detected, when the dog displays PO behavior, accumulates in its olfactory apparatus - the concentration reaches the threshold and the victim is “miraculously” detected. This behavior usually occurs in older dogs. They are the ones who can perform a high-quality “detailed examination”, while young dogs more often, raising their noses, try to catch the smell with their upper senses.

Attachment reaction is the complex behavior of a dog in the form of caressing, obedience, waiting, following the owner, etc. This is an innate behavior based on the “inheritance” received from centuries-old communication and joint actions of a person and a dog. Attachment, supported by care and attention, is the most important reaction, the basis of strong contact between the trainer and the dog, without which its training is impossible. This behavior is the basis of the Swiss method of training PSS dogs. The work of a rescue dog is possible only with a well-developed attachment, since in difficult and dangerous conditions the dog searches for and finds a victim unfamiliar to it, receiving satisfaction and joy from this.

No matter how keen a sense a dog has, the work is reduced to zero without its information connections with the handler. These two-way connections are complex, dynamic and multi-channel. In service dogs they are almost entirely developed through training, in hunting dogs they are largely developed due to innate reactions and natural conditioned reflexes formed in response to natural properties and qualities. unconditional stimuli. For example, a dog develops a natural conditioned reflex to its appearance, voice, individual smell, and certain actions of the handler and his assistant. Extremely important when working with a dog is information feedback: from the dog to the person. The difficulty and complexity of such a connection is due to the fact that the PSS dog, like other services, although it can distinguish odors well, does not know how to react to them and notify, for example, that there is a living person or a corpse in the rubble.

Teaching a dog to react differently to different odor stimuli is the task of its training. In order for the handler to have the opportunity to timely and accurately understand all the dog’s actions related to its work, the odor information perceived and processed by the dog’s olfactory analyzer must, in a conditioned reflex way, include corresponding visual or auditory signals accessible to human perception. Essentially, almost all special training of dogs and the development of their breed qualities in the use of an odor analyzer comes down to the development of reflexes and natural reactions in them that provide feedback from the dog to the person. This communication is carried out by translating the perceived odor information into the language of visual and auditory signals by the animal.

In order for such a connection to be reliable and the transmitted information to be reliable, the development of signal behavior in a dog must be carried out taking into account the stereotype of the working state that is formed, ensuring a balance between stimulants and inhibitory processes. Therefore, for example, not every signal that can be developed in a dog by the skill of a trainer turns out to be appropriate, and not every training technique is rational for teaching PSS dogs.

Biorhythms play an important role for dogs in sense-related work. Ignoring them will not allow you to make the search effective and make the most of its service capabilities. Biorhythms - periodic alternation of a state of greater physical, mental, sensory activity and decreased activity - are divided into external and internal. The manifestation of external ones is associated with periods of solar activity, seasons, time of day and other cyclical phenomena.

Internal biorhythms operate under the influence of the neurohumoral system and endocrine glands. Of particular importance for instinct is the daily biorhythm, which forms periods of greatest efficiency and lethargy. Maximum activity is distinguished - morning (from 8 to 12 o'clock) and evening (from 18 to 24 o'clock), decrease and minimum activity - in the middle of the day and night hours. These hourly data are very approximate and are subject to adjustments for the individual dog and specific environmental conditions.

A complex system of biorhythms requires a clear correspondence between their alternation and the volume and complexity of the work given to the dog. Violation of this correspondence leads to general diseases body, weakening of sense of smell, neuroses.

Sense failure is a partial or complete failure of a dog’s olfactory abilities to perform work carried out jointly with other sensory systems. He nullifies the most high level her training and skill acquired over years of work, negating the chances of the dog finding a victim suffocating in the rubble.

The simplest and fastest-passing breakdown is general physical fatigue or from prolonged work with the upper and lower senses. No less dangerous is overstrain of nervous activity, leading to neurosis. Overheating and hypothermia, reducing the acuity of the senses during work, can subsequently lead to diseases of both the respiratory tract and the entire body.

It should always be taken into account that the dog receives large dose toxic substances compared to humans, since impurities usually settle, the air movement in the ground layer is weaker, which makes it difficult to purify.

If a dog is exposed to the same odor for a long time, the sensation of it weakens, and later he may no longer feel it at all. Adaptation to this smell occurs, explained by a decrease in the intensity of nerve stimulation transmitted from the receptors to the brain. In order for the dog to feel it again, it is necessary to take it out of the area of ​​influence of this smell for a while.

General fatigue during a prolonged search should be distinguished from adaptation due to great physical and nervous activity during muscle load, capture and processing of odor information. Therefore, during prolonged work, dogs should be given a 5-10 minute rest every 50 minutes.

Bad influence The dog's sense of smell is affected by clogging of the respiratory organs with soil, snow dust and smoke. More harmful effects causing functional disorders the nervous system and the entire body are affected by gases and aerosols of toxic chemical compounds. For example, if a dog inhales car exhaust fumes even for a short time, it sharply reduces its sense of smell and can lead to illness and death. In case of rhinitis and other diseases of the respiratory tract, the dog is given rest, since the quality of its search work will be below average, and the tension of the diseased organs will lead to an exacerbation of the disease. Transportation (even if not fast) over long distances from one time zone to another disrupts the body’s biorhythm and sense of smell.

It has been established that the lack of vitamin A in dogs’ food and large amounts of hot spices (pepper, horseradish, etc.) significantly weaken their sense of smell. The olfactory apparatus of dogs is extremely sensitive to external stimuli; even eating a few pieces of sharp cheese weakens the sharpness of its sense of smell for some time.

The PSS dog is a very precise instrument, and therefore it must be treated exactly like a very precise instrument.

Mysteries of smells

In nature, there are a huge number of different odorous substances of animal, plant and mineral origin. All these substances that cause the sensation of smell are called odorants, or odorants, which, according to the duration of their action, are divided into persistent and unstable.

For a dog to detect any persistent and strong odorant, it must not be isolated from the environment. No dog of the highest skill will detect a smell if it is inside a brewed glass container or at the bottom of a flowing river. For a dog to pick up a scent, it is necessary that the source of the smell, that is, the release of odorous particles into the environment, be open. However, at the highest concentration of the odor emitted by the odorant, the effect of the adsorbent - the odor-absorbing substance - and the environment may be so unfavorable that it will be below its threshold concentration - the lowest concentration of the odorant that causes the sensation of smell - for a given dog, at a given moment. The threshold concentration is usually expressed by the number of molecules of a substance per 1 cm 3 of air and is different for different odors.

In addition to the blocking mentioned above, the factors that are detrimental to a dog’s ability to pick up the scent are the following:

1) a thick layer of adsorbent medium (soil, snow, etc.), through which the odor does not escape to the surface;

2) a storm wind that dissipates and carries away the smell instantly. Therefore, for a dog to detect an odor, not only the odorant itself is necessary, but also the following elements:

odorant– presence of IZ – threshold concentration – dog scent picking

Differentiation of odors perceived by a dog occurs only with the coordinated work of its perceiving and analyzing parts of the higher nervous system. Only in this case can the dog identify the desired smell from many others, including those that are very close to it or stronger, and differentiate the individual smell of a person. Of many similar objects, she finds exactly the one that the trainer barely touched with his fingertips, even after being held by other people.

Good dog The search service, when taking a trace of a person, distinguishes his smell from hundreds of others, which may be more recent. The ability of dogs to differentiate odors is based on their use to select the desired person by the smell left by him on the object.

It is curious that dogs, while quickly and accurately distinguishing the smell of what they are looking for from hundreds of people, cannot distinguish the individual smells of two identical twins from each other. This suggests that a person’s individual smell is genetically predetermined, since only identical twins have the same genetic constitution and almost the same individual smell. When the dog was allowed to sniff the scent of one of the twins, it confidently followed the scent of the other. However, if the twins, having laid a common trail, diverged in different directions, the dog followed the trail of the twin whose scent it had sniffed.

The smell of a person is the totality of his individual odor, including the smells of secretions of sweat and sebaceous glands, desquamated epithelium and substances released during pulmonary and tissue respiration. In addition, it includes household, industrial and other impurities that remain mainly on clothes and shoes, as well as the smell of used cosmetics, medicines, etc.

The smell of a person, which is a very complex bouquet, depends not only on the number of its components, but also on their quantitative relationships. Their composition can change not only in terms of quantity, but also quality, which depends on external and internal factors. The first includes temperature and other environmental conditions. The second includes changes in metabolic rate during hard work, the use of medications and odorous foods, and various diseases. Changing it can also cause the accumulation of skin secretions when their constituents are urea and volatile fatty acid begin to decompose.

The smell of a person’s body differs from the smell left on objects, quantitatively and qualitatively. The last difference is explained by the fact that the components of a person’s individual odor are specific and, due to their volatility, cannot remain on objects for a long time. Of these, only the more persistent part remains, which has a slightly different quality.

The odors of decomposing skin secretions are also specific; in addition, in this case, household and industrial odors may predominate. These circumstances allow dogs to distinguish the smell of a person from his smell on objects and from a human corpse.

How acute the sense of experienced dogs is when differentiating the smell of a person from a corpse is evidenced by the following case.

The traveler took refuge in a small cave for the night. In the morning, leaving his hiding place, he fell into a rockfall and died. Soon a rescuer arrived with a dog. She quickly led him to the cave where the deceased spent the night... As the rescuer said, the dog walked a few meters from the frozen corpse, but did not stop, but led further towards the smell of a living person. It was well preserved in the cave, like in an “air closet.” Scientist and clever dog fulfilled the “law of the rescuer” - first to the living, then to the dead. There was no smell of a living person on the corpse.

When working with a dog, it should be taken into account that human odor is well absorbed and retained by wool and silk fabric, worse than paper and synthetic fabric. Its smell is well adsorbed by soil, dry wood, especially strongly charcoal. Odors are destroyed by exposure to the rays of the sun, oxygen, ozone and a number of other agents. Therefore, in the search service, depending on the age of the trace laid by a person, that is, on how weakened its smell is by the time the dog traces it, it is customary to divide the traces into fresh, normal and old (more than 3 hours).

Man as a “source of smell” has many similarities with animals. This also applies to the release of volatile components into the environment. Many of them carry information about the species, sex, individual, its physiological, functional and emotional state. In addition to the permanent characteristics of an individual, these components can also reflect temporary, random ones - the place of recent stay, food eaten, disruption of the functioning of any organ or the entire organism.

Contamination of the victim's clothing with strong-smelling substances - gasoline, technical oils, various chemicals - makes it difficult to find him. Although the dog also senses the smell of the person himself, he reacts less well to it as the desired smell. A kind of anosmia occurs, like a cop's response to the scent of a hare's footprint.

In order for a dog to catch an odor at some distance, its concentration in the air between the source and the dog must be no lower than the threshold. When the air is completely still, which almost never happens in real conditions, the smell on the surface of the earth spreads by diffusion evenly in all directions, in the form of an irregular sphere. The rate of diffusion is not constant; it depends on atmospheric pressure, air temperature, molecular weight of odorous particles and other factors. The spread of odor in the absence of wind also occurs by convection, that is vertical movement air between the upper and lower layers of the atmosphere, resulting from their uneven heating. It is also not constant and depends on the above factors.

The upward movement of air with odor particles reduces their number in the ground layer and makes it difficult for the dog to pick up the scent. Of course, during training sessions the trainer will not calculate according to which law the smell is released. His task is to understand these laws, not to act blindly and not to demand the impossible from the dog - to detect the smell where its concentration is below the threshold or there is none at all. In a real rescue situation, in a “hopeless situation,” sometimes it is necessary to stop the fruitless search and shift attention to where the victims can still be found and rescued.

Odor coming to the surface

In order for the smell of a person trapped under a layer of soil or snow to be picked up by a dog on the surface, it must first pass through this layer, which has a certain density that can block its exit or be such a good adsorbent that it will absorb most of the smell.

There are 4 main types of media through which odor escapes from the rubble.

1. Ruins of buildings, forest rubble. The debris of destroyed buildings and tree trunks, mixed together as a result of an earthquake or hurricane, leave such large gaps that the free passage of human smell through them is possible through a thickness of 10 meters or more. In cold weather, the release of odors to the surface increases due to the law of convection. Factors that make it difficult for a dog to smell include an abundance of household items with a human scent, smoke in the air from fires, and a large amount of dust.

2. Combined rubble. Debris of destroyed buildings, tree trunks mixed with wet soil or snow as a result of a mudflow or an avalanche of wet snow make it difficult for the smell to reach the surface. It occurs more actively in crevices near protruding large fragments of wood and stones. The rapid compaction of the mud mass and the freezing of snow make it difficult to pick up the smell.

3. Avalanche removal, snow drift. The layer of snow formed after these disasters has a different structure and transmits odors differently. The most favorable conditions for the smell to come to the surface are large, not wet and not frozen, lumpy snow, which has fairly large through pores. The passage of the smell is complicated by high humidity and density, a dusty structure, an ice crust on the surface and the extremely variable state of the snow.

4. By example forest blockage serves as a search for lumberjacks in Altai...

After hurricane winds and thunderstorms, avalanches occurred in a large area in the foothills and a forest fell. According to the forestry department, 3 loggers worked in the littered area. The debris was of a mixed nature - fallen, broken tree trunks, branches mixed with wet avalanche snow. The dog, which began searching with its guide, fell headlong into cedar branches mixed with frozen snow. She moved with difficulty, breathing heavily. The physically difficult and dangerous movement of the dog and the handler made it difficult to navigate and conduct a clear search. The guide pulled up the tent and ordered the dog to stop searching.

In the morning, the frozen snow held the branches and branches tightly - it was easy to walk. The dog sniffed sensitively, mainly with its lower sense. She moved slowly, stopping, sticking her nose between the branches... It was the second hour of searching. But the guide did not urge her, did not urge her to look faster. The sun was rising, the ice crust on the snow was melting. Here the dog attacked the rubble, loud barking - the first lumberjack was found. Half an hour later, encouraged by the discovery of the first one, the dog found the other two lumberjacks.

The physical explanation for the release of the smell for the dog to take it is as follows. Over the course of a few night hours, the smell of a person sufficiently diffused the mass of the rubble. In the early morning, at the lowest air temperature, convection intensified. The rays of the rising sun melted the ice crust of the rubble, and the smell of lumberjacks appeared on the surface.

The “physiological” side is no less important. In the morning and during the day, the dog did the search several times better than in the evening for the reason that its “sense itself” was several times sharper. The road to the scene of the incident, the physical stress of moving through a difficult and dangerous blockage, and the novelty of the blockage itself had an effect on the dog, just like any other, bad influence. There was a generalization of the central nervous system instead of the concentration necessary for conducting an effective search, that is, the concentration of all forces and attention for one goal - finding the smell of a person.

The guide, in all respects, acted absolutely correctly in choosing such search tactics.

According to A.P. Orlov, the founder of the Russian Ore Detection Dog Service, recorded cases of dogs picking up the smell of ore located under a layer of water, above which there was also a layer of swamp soil.

This is a very complex process that occurs infrequently due to the relationships between meteorological and geological conditions: the smell of ore saturates the water - water saturated with the smell, according to the “law of the wick” (the phenomenon of capillarity), rises through the soil to its surface and spreads in the air. Therefore, searching in an environment where water squishes under your feet is far from empty. At very low, “subthreshold” odor concentrations, dogs are helped by its accumulation by the olfactory organs.

Wind influence

The most favorable conditions for odor transfer by wind are created by flat, open areas with low vegetation cover. Thus, when a dog works with its upper sense, when it performs a “primary” search, the wind is an facilitating factor.

However, when the dog switches to a “thorough” search, when it uses its lower sense, the wind is more likely to cause harm. It has been established that with distance from the odor source, the amount of odor information received decreases in proportion to the square of the distance. But it is not the remoteness of the source that is main reason weakening of the odor, namely unfavorable speed and nature of the wind. The optimal speed for a dog to work with its lower sense is considered to be a speed of up to 0.5 m/sec. The reduction in the receipt of odor information in strong winds occurs not only from the mechanical dispersion of odor particles, but also due to their chemical transformation under the influence of increased amounts of oxygen and ozone.

When searching, you should always take into account that the dog receives the maximum smell not from a direct headwind, but from a counter-side wind at an angle of about 30°. This is explained anatomical structure the olfactory apparatus of animals, thanks to which, while in motion, they explore with the help of their senses a much larger territory with such a wind than with a direct oncoming wind.

Influence of other weather conditions

When the PSS dog completes the search for the victim, determining his exact location, and works mainly with his lower sense, the success of this operation, in addition to the wind, is influenced by a number of factors. The most important of them is air humidity, an increase in which helps its work. This is explained by the fact that with increasing humidity, the desorption process slows down, that is, odor particles break off more slowly from the soil surface and spread longer in the surrounding air.

Low humidity negatively affects the dog's olfactory apparatus, drying out the mucous membrane of the nasal cavity. Light drizzle, increasing air humidity, has a positive effect. Heavy and thunderous rain washes away the smell from the surface, but does not prevent it from leaving the depths of the soil and snow. The formation of ozone in the air, which actively destroys odor particles, has a negative effect.

High temperatures of the soil surface and air have a negative effect on the dog's work. The heated soil surface promotes more active flow of chemical reactions oxidation of odor particles. In addition, the heated soil heats up the ground layer of air, active convection occurs and the odor concentration below decreases. Heating the air, in addition to activating these processes, leads to overheating of the dog’s body, drying out the nasal mucosa, shortness of breath and fatigue.

Notes:

Service dog breeding / Comp. V.N. Zubko. M., 1987.

Inaccurate names and expressions found in the literature on dog breeding make it difficult to understand the topic being presented. “Behavioral reaction” is a lexical inaccuracy. In animals, as in humans, certain reactions of the body occur in response to stimuli received by the nervous system. There are no behavioral reactions, since all behavior is a chain of reactions. That's right - “indicative type of behavior”, “indicative search behavior”. - Note here and below. auto

The animal world is divided into microsmatics and macrosmatics. A person is a microsmatic person and perceives the world through hearing and vision. Dogs, in addition to hearing and vision, are endowed with the ability to perceive the world by smell. This ability of dogs has become useful for humans and has found application in some services, but for this it was necessary to study the physiological features of the four-legged friend.

How do animals find objects and people?

A dog's moist, mobile leather nose is several thousand times more sensitive than the human nose. Scientists have proven that dogs can smell one molecule of aromatic substance per liter of air, and can also smell one molecule per milliliter of water. A dog perceives a huge number of odors, and it senses them not together, but separately. An important fact is that they can also remember smells and associate them with scents in their past. This indicates the perception of the environment through the prism of smells.

Thanks to the German physiologist Neuhaus and his olfactometer It was possible to determine the depth of the dog’s sense of smell. The experiment showed that the susceptibility of a dog and a person to some odors differs little, and there are some aromas that a dog will perceive more strongly than a person. These include some fatty and butyric acids. After conducting several experiments, the scientist concluded that a dog can distinguish a person not by his personal smell alone, but by a set of substances that take part in creating the individual smell of a particular person.

After Lochner's experiment it became clear that dogs could easily distinguish between unrelated people. It is not difficult for them to distinguish between relatives. Sometimes problems arise with identical twins. Dogs don't separate them. They find one of the twins by the object, even if both touched it.

In 1885, George Romanes conducted an experiment. Romanes led a column of twelve men. The column walked one after another, stepping on the footprints of the one in front. After a hundred meters they separated and went in different directions. After walking a little, those walking hid. His dog was set on Romanes' trail. The dog completed the task. At first he missed the place where the column split, but when he returned, he found his owner. This experiment showed that a dog can smell even a weak odor, clogged with other, stronger ones.

A dog can distinguish twenty-five thousand scents. Among these odors there are always more important ones for the animal. You can understand this by watching dogs. They sniff some smells for a very long time, while they barely turn their nose at others.

Sergei Korytin published data in 1975 in which he showed that mongrels spent thirty-five seconds sniffing the secretions of other dogs, and only spent twenty-five seconds studying the smell of food, and the smells of plants and essential oils It only took them five seconds. This proves that the smells of their own kind and other animals are much more important for them than all other aromas.

In addition to the search service, dogs help look for mold. This type of activity is common in Sweden. In this country, every few years a special service checks telegraph poles for mold. They are helped in this by dogs who have undergone special training. Four-legged controllers practically do not make mistakes. Training a dog is expensive - two hundred thousand Swedish crowns, but this cost is recouped within six years.

The sensational story of the disappearance of a football cup, which was found in the bushes homeless dog, was the impetus for using dogs to search for minerals. Finnish scientist Professor Kahma conducted an experiment with the participation of his dog Lari, who managed to discover ore deposits. After this, with the help of dogs, a deposit of tungsten and nickel was discovered in the USSR.

They began to use dogs to search for gas leaks on the gas pipeline.

Dogs inherited their amazing sense of smell from their wild ancestor. To the ignorant it may seem that the wolf receives all information through hearing and vision. But this is not so; he does the final check with the help of his nose. A wolf can find a trap with the scent of human hands through a meter thick layer of snow. And he can smell his prey a hundred meters away.

Smells play a huge role in a dog’s life, and a person will need a lot of time to decipher the language of scent. Therefore, a dog’s sense of smell will be in demand by humans for a long time. And it’s not just that there are no technical devices that can completely replace a dog’s nose. It is difficult to break a partnership that is more than one millennium old with one stroke, replacing a wet and moving nose with a device.

A dog's nose, its sense of smell - amazing world smells, about which a person has an approximate understanding. Humans have approximately 5 million olfactory cells, while the average dog has more than 125 million. The cerebral cortex responsible for smell is larger in dogs than in humans. In this article we will discuss the dog's nose, how it is and its abilities.

Dog's nose, its structure

The dog's nose is covered with mucus. This is exactly the mucus that a person has inside his nose. And in a tailed friend, this mucus covers most of the nose not only from the inside, but also from the outside. The mucus produced by the glands of the lining of the nose is a kind of filter through which molecules of odorous substances are analyzed by the animal. We have already touched on this topic. Now let's talk about smell in more detail.

The structure of the nose itself is amazing. The nostrils of furry pets have been thoroughly examined by scientists. And this is what scientists have found out about the nostrils. The side cutouts of the nostrils play vital role in odor recognition. If a dog simply inhales air, then about 47 percent of the air enters through the side openings of the nostrils; when sniffing, it is already 53 percent.

Also, the dog receives information not only during inhalation, but also during exhalation. If she breathes through her mouth, then part of the incoming air does not pass into the lungs and, when exhaled, exits through the nostrils, where the air is processed by the nasal receptors and analyzed.

However, when breathing through the mouth, air enters only through the round nostrils, without affecting the side cutouts. This means that the quality of the sense of smell is decreasing, since new odors cannot be detected.

If the dog is calm, then the nostrils can collect information from the air in front and from the sides. There is an air space right in front of the dog's nose, from which air is not drawn in by the nostrils. It is 60 degrees, 30 degrees for each nostril. In a calm state, the coverage sector of the air mass ranges from 30 to 130 degrees from each nostril.

But if the dog’s nose is alert, then the side cutouts fold in such a way that they can absorb air from behind. In this case, the dog does not even need to turn his head, since the coverage sector is already from 30 to 150 degrees from each nostril.

It turns out that the side cuts of the nose are an important tool with which the dog is well oriented in space. Studies have been done where dogs have these side cuts sutured. And then they immediately lost the ability to orient themselves in space using their sense of smell.

Why does a tired dog's nose work worse?

It is common knowledge that a tired dog begins to smell poorly and needs to rest. This happens because during physical activity the animal increasingly switches to mouth breathing. This means that only 5-15 percent of air enters through the nose. This is not enough for in-depth analysis of odor recognition. Therefore, the pet needs to rest. When the dog is sniffing thoroughly, its breathing should be deep and slow.

A dog's nose is unique. He can differentiate smells. A person is practically incapable of such a thing. Only high-class professionals can break down the overall smell into its components. Whereas any dog ​​is capable of analyzing odors, looking for even a very small amount of an odorous element against the background of other, rather strong odors. It is this quality that people use when they hire a furry friend.

What can a dog's nose detect?

Dogs help people not only in searching for drugs or people. Our tailed friends are also successful in other areas. For example, in Sweden, about 70 percent of buildings are infected with mold. Of course, damaged parts of the structure need to be replaced, and 200 dogs work daily in tandem with a microbiologist, finding exactly the right types of bacteria in houses by smell.

Interestingly, dogs recognize some odors better to one degree or another. For example, they are better at finding drugs than searching for the smell of fruit. At US airports, the transport of small quantities of vegetables and fruits is prohibited, and only a few animals are able to work in these places, recognizing the smells of apples and carrots.

What affects a dog's sense of smell?

Some external factors may affect the quality of smell.

• Temperature factor. At high temperature the dog becomes lethargic, the body overheats and it has difficulty hearing odors, as it begins to breathe through its mouth. This mechanism was written about a little higher. The most optimal temperature limits are from 25 degrees Celsius to 15 degrees below zero. At high temperatures, odor particles evaporate faster, and at low temperatures they remain, but the nose can no longer perceive them well enough.
• Humidity. With high humidity, odor particles remain in the field of smell. The best weather for a dog may be weather with high humidity. For example, when it is raining lightly or there is fog. But the rain will wash all the smells into the ground.
• The wind can play both a positive role in detecting a trace and a negative one. Strong wind carries away and dispels odor particles. However, the wind helps the particles evaporate from the ground and be felt.
• Atmosphere pressure. When it decreases, the evaporation of particles increases and it is easier for the animal to pick up the trail.

The acuity of smell is also affected by internal factors . The fatigue of the dog and the loss of its sense of smell have already been written here. Nutrition also affects your sense of smell. For a good sense of smell, she must receive at least 16% fat. Before the next hunt, hunters do not give their pets meat for some time. Its absence in the diet will allow the dog to better search for game.

With age, the sense of smell weakens. Of course, any even very unnoticeable cold may also affect the acuity of smell. Any anatomical changes in the structure of the nose can in various ways affect the instinct.

Turning off one sense organ increases the sensitivity of another. Interestingly, the best sniffers are pointers (this includes all pointers, setters, griffons and others), greyhounds, dachshunds, spaniels and other hunting dogs that have ears that fit tightly to the head. So far scientists cannot explain this fact.

Among the watchdogs there are also many representatives with drooping ears (if they were not cropped in puppyhood): Caucasian and Central Asian Shepherd Dogs, Rottweilers, St. Bernards, divers and others. It turns out that people have noticed this feature since ancient times and selected dogs in such a way that their olfactory abilities came to the fore.

Now, based on the data obtained, you can better understand your dog and its behavior. And in conclusion, I suggest you watch a wonderful video about a beagle, which helps passengers at Amsterdam Airport find forgotten things.