Class mammals, or animals. Narrowing of the left atrioventricular orifice

A basic level of

For each task, choose one correct answer from the four proposed.

A1. Breastfeeds cubs with milk

1. penguin
2. crocodile
3. heron

A2. Sebaceous and sweat glands are located in the skin

1. squirrels
2. lizards
3. penguin
4. partridges

AZ. Unlike reptiles, the structure of the skeleton of mammals changes significantly

1. skulls
2. shin bones
3. upper limb belts
4. caudal spine

A4. Unlike reptiles, the hearing organ of mammals includes

1. middle ear
2. eardrum
3. auricle
4. cochlea of ​​the inner ear

A5. The organ of gas exchange in the dog's respiratory system is

1. alveolar lungs
2. bronchi
3. trachea
4. larynx

A6. During the development of an embryo in animals, the placenta, or baby's place, is formed in

1. uterus
2. ovary
3. oviduct
4. testis

- - - Answers - - -

A1-4; A2-1; A3-1; A4-3; A5-1; A6-1.

Increased difficulty level

B1. Are the following statements true?

A. Representatives of the order Cetaceans - dolphins and whales - breathe with gills.
B. In marsupial mammals (kangaroos, opossums), the young are born underdeveloped, and their further development occurs in the mother’s pouch.

1. Only A is correct
2. Only B is correct
3. Both judgments are correct
4. Both judgments are wrong

B2. Choose three true statements. Representatives of the rodent order are

1. jerboa
2. bat
3. marten
4. rat

BZ. Establish a correspondence between the characteristic of life activity and the class of animals for which it is characteristic.

Features of life

A. Maintaining a constant body temperature
B. Reproduction by eggs or ovoviviparity
B. Variable body temperature
D. Most representatives are characterized by viviparity

Animal class

1. Reptiles
2. Animals

Write down the corresponding numbers in the table.

B4. Establish the sequence of occurrence during the evolution of classes of chordates.

1. Reptiles
2. Mammals
3. Amphibians

- - - Answers - - -

B1-2; B2-236; B3-2112; B4-2413.

The dog's respiratory organs are represented by the upper respiratory tract and lungs. The upper respiratory tract includes the nostrils, nasal passages and cavities, nasopharynx, larynx, trachea and major bronchi. The inhaled air, passing through them, is subjected to thermoregulation and purification from mechanical particles (dust). The mucous membrane lining the upper respiratory tract has bactericidal properties. Therefore, microbes die in the upper respiratory tract, and sterile air enters the lungs.

For dogs, the function of chemical analysis of inhaled air is of particular importance. The receptor apparatus of the olfactory organs is located in the nasal passages. Before taking a deep breath, the dog takes frequent shallow breaths, during which the air is in continuous contact with the receptor apparatus, and the animal receives rich information about the external environment. This behavior is especially noticeable in dogs in unfamiliar surroundings. Obviously, a dog trusts his sense of smell more than a human. During a walk, the dog walks around “its” territory, evaluates it with the help of its olfactory organs, not forgetting to leave scent marks.

The mechanism of inhalation and exhalation occurs due to the contraction of the respiratory muscles - the diaphragm and the muscles of the chest. When inhaling, the external intercostal muscles and the diaphragm contract.

The volume of the chest increases, due to the vacuum in the pleural cavity, the lungs stretch, and air passively fills them. When the respiratory muscles relax, the chest decreases in volume and air is squeezed out of them. Exhalation occurs.

The frequency of respiratory movements is regulated by the central nervous system, the functional activity of which depends on the concentration of carbon dioxide, oxygen and blood pH. At rest, medium and large dogs make 10-30 movements, small animals breathe more often.

Gas exchange itself occurs in the lungs as a result of the difference in the partial pressure of oxygen and carbon dioxide. The partial pressure of oxygen is higher in the alveolar air, so it passes into the blood. In the case of carbon dioxide, the picture is the opposite: in venous blood the partial pressure of CO 2 is higher than in the alveolar air, and carbon dioxide actively passes from the blood into the alveoli of the lung tissue.

Oxygen transport in the blood occurs with the help of hemoglobin in red blood cells, and carbon dioxide transport occurs with the help of carbonates and bicarbonates in the blood plasma.

NON-RESPIRATORY FUNCTIONS OF THE RESPIRATORY ORGANS

Along with the inhaled air, foreign or even harmful substances and particles can enter the respiratory system in the form of aerosols or gases. However, after contact with the mucous membrane of the upper respiratory tract, most of them are removed from the body. The depth of penetration of foreign air components depends on the size of these particles. Large particles (dust), the size of which exceeds 5 microns, are deposited on the mucous membrane due to inertial forces in places where the bronchi bend. Heavy particles cannot go around the bend of the bronchi and, due to inertia, hit the wall of the bronchus. Using the same scheme, the air is also freed from particles ranging in size from 0.5 to 5.0 microns. However, this process already occurs in the bronchioles of the lungs. Particles smaller than 0.5 microns penetrate the alveoli of the lungs and penetrate the mucous membrane of the respiratory epithelium.

The nature of breathing has a great influence on the retention of foreign particles in the upper respiratory tract of a dog: when it is slow and deep, microparticles penetrate into the lungs; when it is frequent and superficial, it helps to cleanse the air in the upper respiratory tract.

Thus, particles adsorbed on the mucous membrane of the upper respiratory tract are expelled towards the nasopharynx or nasal passages due to the oscillatory movements of the ciliated epithelium. Then they are either swallowed or thrown out into the external environment due to a sharp exhalation (sneezing). In the pulmonary alveoli, foreign particles undergo phagocytosis by macrophages. Bacterial cells are exposed to bactericidal substances in the mucus of the pulmonary epithelium (complement system, opsonins, lysozyme). As a result, all corpuscular particles are destroyed or transported by macrophages outside the respiratory organs.

Lung macrophages are adapted to the conditions of the alveoli, that is, they are active in an oxygen-rich environment. Therefore, hypoxia suppresses phagocytosis in the lungs. Stressing an animal is also accompanied by a decrease in the protective properties of the respiratory organs, since corticosteroids suppress the activity of macrophages. A viral infection leads to a similar result. Alveolar macrophages constitute the dog's front line of defense. In the case when a large number of corpuscular particles are inhaled, other phagocytes come to the aid of macrophages - primarily blood neutrophils.

However, with excessive activity of phagocytes, the reactive oxygen radicals and proteolytic enzymes they release can damage the epithelium itself, lining the pulmonary alveoli. To restrain the excessive activity of phagocytes, protease inhibitors (α-antitrypsin) and antioxidants (glutathione peroxidase) enter the mucus of the pulmonary epithelium. These substances protect the lungs from the damaging effects of the respiratory system's own protective system.

The penetration of harmful gases in the respiratory air into the dog’s body depends on their concentration and solubility. Gases with high solubility (for example SO 2) in small concentrations are retained in the nasal cavities due to adsorption on the mucous membrane, but in large concentrations they penetrate into the lungs.

Gases with low solubility reach the pulmonary alveoli in an unchanged state. However, toxic gases stimulate protective mechanisms such as bronchospasm, hypersecretion of mucus, coughing and sneezing, which block their diffusion or provide mechanical removal from the respiratory system.

Having a huge area of ​​capillaries (a reactive surface with fixed enzymes), a high oxygen supply and a developed cellular antitoxic system, the lungs are an ideal place for thoroughly purifying the blood from biologically active and, therefore, potentially dangerous metabolites. Thus, the endothelial cells of the pulmonary capillaries absorb the entire volume of serotonin produced in the dog’s body. A number of prostaglandins, bradykinin and angiotensin are also metabolized here. Neutrophils found in the lungs ensure the destruction of leukotrienes.

Macrophages of the respiratory organs are related to the regulation of fat metabolism. The fact is that blood with a high level of lipids enters the lungs. High lysing activity of macrophages in relation to lipoproteins entering the body with lymph from the gastrointestinal tract was noted. As a result of the absorption of lipoproteins by macrophages, the latter increase in size (mast cells), and the blood is cleared of excess fatty substances. With active blood flow and hyperventilation of the lungs (physical activity), excess fat is oxidized and removed from the body in the form of thermal energy with exhaled air.

Dogs breathe differently in high temperatures - shortness of breath is a normal physiological phenomenon. The respiratory rate under these conditions can exceed 100 per minute. The physiological meaning of shortness of breath is hyperventilation of the upper respiratory tract and lungs in order to increase evaporation from the mucous membrane. The evaporation of moisture is accompanied by cooling of the surface of the upper respiratory tract and lungs and the blood flowing to them. Consequently, in dogs, the respiratory organs also perform the function of thermoregulation in conditions of elevated temperatures.

Thus, the physiological role of the dog’s respiratory organs is not limited to gas exchange. The dog's respiratory system is involved in immune reactions, metabolism, and thermoregulation of the body.

FEATURES OF THE DIGESTIVE SYSTEM

The digestive system is one of the most flexible physiological systems, which ensures relatively rapid adaptation of animals to a wide variety of sources of proteins, fats and carbohydrates. The dog is an omnivore, although its ancestors were mainly predators. The dog's digestive system has been studied in great detail. She has a rather short gastrointestinal tract, well adapted to use mixed diets, including both animal and plant foods.

The dog grabs food using its incisors. Mechanical processing of food in oral cavity quite superficial: the animal cuts the meat into large pieces, crushes them with its molars and swallows, i.e., the food is not thoroughly crushed in the dog’s mouth.

If the dog is very hungry, then it can swallow very large pieces, practically without chewing them. True, often after such a meal the dog regurgitates the contents of the stomach and chews the food again.

It is believed that the dog grasps food using the incisors, the premolars and molars (especially the 4th upper and 5th lower) provide crushing. Fangs are a killing weapon for hunters and a fighting weapon in fights for other dogs.

The age of dogs is determined by their teeth. The first baby teeth appear in puppies at the age of two weeks. A full set of baby teeth is formed (depending on the breed) at the age of 1-2 months. For example, in German Shepherd puppies, at the age of 5-6 weeks, all baby teeth are counted. And in Miniature Schnauzer puppies, a full set of teeth is formed later - at 7-9 weeks of age.

Normally, by the age of 6 months, all baby teeth are replaced with permanent ones. Starting from 12-18 months of age, noticeable tooth wear begins, and this phenomenon occurs at the same speed in most dogs, i.e. it is a general biological phenomenon. There is a prejudice that the degree of tooth wear determines the nature of nutrition. In particular, bones speed up this process. Our personal experience with dogs suggests the opposite: bones strengthen the jaws and improve blood supply to the gums.

The basis for determining the age of a dog is the rate of abrasion, primarily of the upper edge of the incisors. So, by the 2nd year of life, the teeth at the hooks wear out; to the 3rd - this process captures the middle incisors; by the 4th - the teeth disappear on the edges; by the 5th year of life, the teeth are visible only on the upper edges; by the age of 10, the incisors have a reverse oval edge; by 12, some incisors begin to fall out; By 14, canines, premolars and molars begin to fall out. The above diagram is quite approximate, and individual individuals do not fit into it. Thus, the 15-year-old Mittelynna-utser known to us can be given no more than 2 years of age based on the pattern of tooth abrasion.

In addition to mechanical processing, food in the oral cavity is exposed to saliva. Three large paired salivary glands open into the oral cavity - the parotid, submandibular and sublingual. In addition, on the dog's tongue, cheeks and lips there are multiple small salivary glands that secrete mucus.

Dogs salivate when they see, smell, or eat food. Salivation is especially strong in dogs when they chew something, such as a bone. The total amount of saliva per day reaches 1 liter in a medium-sized dog. However, the level of salivation is highly dependent on the moisture content of the feed. Dry food like “Chapi” produces more saliva than liquid soup.

Under the influence of saliva, the dry food is moistened and the food bolus becomes slimy. Moistening of the feed is provided mainly by the saliva of the parotid glands - it is quite liquid. The saliva of the submandibular and sublingual glands is mixed, that is, it wets and licks food. Small mucous glands secrete saliva containing a mucus-like substance - mucin.

After this treatment, the food lump is easily swallowed by the animal. Saliva contains glycolytic enzymes, i.e. enzymes that act on the carbohydrate part of the feed. Therefore, carbohydrate food is partially broken down in the dog’s mouth. But taking into account the short duration of the food’s stay in the dog’s mouth, a deep transformation of carbohydrates in the dog’s mouth is unlikely.

Dog saliva is highly bactericidal due to the presence of lysozyme, a substance that can destroy the bacterial cell wall. Consequently, in the oral cavity the food is partially disinfected under the action of saliva. The same reason underlies the high effectiveness of dog licking wounds. By licking a wound on the body, the dog cleans it of dirt, performs bactericidal treatment of the wound and, in addition, due to salivary kinins, increases the rate of blood clotting in damaged vessels.

The stomach of dogs is simple, single-chamber, only partial digestion of food occurs in it, and only proteins and emulsified fats undergo deep transformation.

Digestion in the dog's stomach occurs under the influence of gastric juice, which includes hydrochloric acid, enzymes, minerals and mucus. The secretion of gastric juice is carried out according to certain laws, which at one time were studied in detail by our outstanding compatriot, Nobel Prize laureate in physiology I. P. Pavlov.

In accordance with modern concepts, the secretion of gastric juice occurs in three phases.

First phase- nervous. The sight and smell of food leads to the release of so-called inflammatory gastric juice. Nervous excitement associated with the anticipation of food leads to the fact that nerve impulses from the central nervous system excite the intramural nervous system of the stomach, which, in turn, stimulates the secretion of gastrin and hydrochloric acid by the cells of the gastric wall. Gastrin stimulates the nerve endings of the intramural nervous system of the stomach, which leads to the release of acetylcholine. Acetylcholine paired with gastrin excites the lining cells of the digestive glands of the stomach, which causes even greater secretion of HCL.

Second phase- neuro-humoral - is ensured by ongoing nervous stimulation, irritation of the receptor apparatus of the stomach and absorption of extractive substances of feed into the blood. A complex of enzymes as part of gastric juice is secreted into the lumen of the stomach.

Third phase gastric juice secretion is purely humoral. It develops as a result of the absorption of hydrolysis products of proteins and fats into the blood.

While gastrin is being secreted, the pH value of the gastric chyme is constantly decreasing. When the pH reaches 2.0, inhibition of gastrin secretion begins. At pH 1.0, gastrin secretion stops. At such a low pH value, the pyloric sphincter opens and gastric chyme is evacuated in small portions into the intestine.

A dog's gastric juice contains many proteolytic enzymes: several forms of pepsin, cathepsin, gelatinase, chymosin elastase (the latter is found in large quantities in the gastric juice of suckling puppies). All these enzymes break the internal bonds of long protein chains of food. The final fragmentation of protein molecules occurs in the small intestine.

The role of the stomach in fat digestion is limited to emulsified fats. Fat emulsion is a mixture of tiny fat particles and water molecules. The prevalence of fat emulsions in dog foods is very limited. An example of emulsification of fats is only whole milk. Therefore, gastric lipase is most active in puppies during the suckling period. In adult dogs, there is virtually no digestion of fats in the stomach. Moreover, fatty foods also inhibit gastric digestion of proteins.

IN thin department intestines All feed nutrients - proteins, fats, carbohydrates - undergo deep breakdown. Pancreatic enzymes, intestinal juice and bile are involved in this process.

Here, in the small intestine, absorption of hydrolysis products occurs. Proteins are broken down and absorbed in the form of amino acids, carbohydrates - in the form of monosaccharides (glucose), fats - in the form of fatty acids, mono-glycerides and glycerol.

In a dog large intestineka relatively short. Nevertheless, it has its own irreplaceable functions. In particular, the absorption of water and mineral salts dissolved in it occurs in the large intestine. In the large intestine, although limited, under conditions of poor nutrition, the vital synthesis of B vitamins and essential amino acids occurs.

It should be said that biologically active substances synthesized in the colon by symbiotic microbes can no longer be absorbed practically in this part of the intestine. Consequently, this synthesis makes biological sense only in cases of autocaprophagy, i.e., eating one’s own excrement during forced starvation of dogs.

The large intestine in its wall has a huge number of lymphoid formations, which are related to the body's immune defense, for example, the formation of |3-lymphocytes.

Bowel motor function very pronounced in dogs. It is represented by three types of contractions - worm-shaped, pendulum-shaped, segmenting peristalsis and antiperistalsis. Worm-like peristalsis ensures the movement of food gruel through the digestive tube. Pendulum-shaped and segmenting - mixing chyme with digestive juices. Antiperistalsis for a dog is an absolutely normal phenomenon:

when the stomach is full, the dog is freed from excess food;

when consuming cartilage and bones, secondary, more thorough processing is often required, which is what the dog does after belching.

The following behavior can be observed in many lactating bitches with a highly developed maternal instinct: the dog clearly eats more than it can, and then regurgitates food for the puppies.

A medium-sized lactating female ate almost a bucket of food waste in the backyard of one cafeteria. Then she moved with great difficulty towards her kennel (while her stomach was literally dragging along the ground). Finally reaching the kennel, she vomited the contents of her stomach onto the puppies. Thus, using her own stomach for transportation, she created a large supply of food for the puppies. Moreover, the regurgitated food mass also seemed more preferable for adult members of the dog pack compared to unprocessed food.

The gastronomic preferences of dogs often shock their owners. Even among city dogs provided with adequate nutrition, the phenomenon of caprophagia, i.e., eating the feces of other animal species (horses, cattle and humans), is common.

When slaughtering sheep and cattle, several dogs (domestic and stray) were given the right to choose. After slaughter and opening of the abdominal cavity, all dogs gave preference to the gastrointestinal tract, i.e., gastric and intestinal chyme turned out to be more attractive compared to meat. This phenomenon is quite normal and understandable. Chyme contains semi-digested nutrients and, in addition, is rich in vitamins of microbiological origin and minerals of endogenous origin.

Eating chyme and caprophagia is a way to satisfy the dog’s needs for biologically active substances and easily digestible nutrients. This type of dog behavior should not be considered abnormal. Objections on the part of people in this matter are purely aesthetic.

The frequency of defecation and the amount of feces produced in dogs varies depending on the breed (live weight), the amount of daily ration and the frequency of feeding.

The apex of the nose does not contain glands. It is based on the nasal cartilage and the cartilaginous septum. The nasal planum is usually pigmented. Along the midline there is a continuation of the groove of the upper lip - the filter. The nostrils narrow into a slit bordered by the upper and lower wings, which are inactive. Short-headed dogs often have difficulty breathing noisily, accompanied by wheezing - due to too narrow nostrils.

The structure of the dog's dorsal shell is common for the anatomy of carnivores. The ventral shell is large and strongly folded. The middle passage is divided into two arms by the far-penetrating endoturbinal of the ethmoid labyrinth (middle concha). The labyrinth of the ethmoid bone itself is also significantly complicated. Due to these features, the surface of the olfactory epithelium in dogs ranges from 67 cm2 (spaniel) to 170 cm2 (shepherd), and the number of olfactory neurons can exceed 200 million.

Respiratory system of a bulldog (side view)

The larynx is located at the level of the I–II cervical vertebrae and has an almost cubic shape. The main cartilages of this organ are the elastic epiglottis, two arytenoids, the short thyroid cartilage and the large annular cartilage. The structure of the dog's larynx can also be supplemented by a small flat interarytenoid cartilage and sphenoid cartilages. The latter lie on both sides of the epiglottis and are attached to the arytenoid cartilages by connective tissue.

The trachea has a cylindrical shape, is somewhat flattened dorsoventrally, and contains 42-46 cartilaginous rings. The bifurcation is located at the level of the 4th rib.

The lungs are divided into lobes by deep incisions from the base of the lobar bronchus. The apical (cranial) lobe of the right lung is bifurcated. The cardiac (middle) lobes of a healthy dog ​​do not extend laterally beyond the diaphragmatic (caudal) lobe. The caudal vena cava is surrounded superiorly by an accessory lobe. The right and left pleural sacs communicate in the posterior part of the mediastinum.

Respiratory system of a bulldog (frontal view)

Diseases identified during examination of the respiratory system

External respiration provides air warming, its transportation and purification from large-dispersed impurities (dust, microorganisms). This type of breathing is carried out through the nose, larynx, trachea, bronchi and lungs. Diseases of these organs lead to disruption of the functions of gas transport and gas exchange, which entails hypoxia. What is common in the pathogenesis of all diseases of the respiratory organs is that compensatory processes are not always able to eliminate oxygen starvation of tissues. Pulmonary decompensation occurs, accompanied by symptoms of cyanosis. The development of fibrous tissue is stimulated due to excess carbon dioxide in the body. The physiological capabilities of organs are reduced.

Etiologically, all diseases of the respiratory system are associated with viral (plague) or bacterial (pneumonia) infections.

When examining the respiratory system, it is necessary to focus on the following points:

– frequency, rhythm, symmetry of respiratory movements and type of breathing (presence of cough, shortness of breath, etc.;

– the smell of the air exhaled by the dog;

– the condition of the nasal mucosa, the presence or absence of discharge, its nature;

– condition of the accessory cavities, larynx, trachea;

– palpation and auscultation examination of the lungs and chest.

Rhinitis

¦ ETIOLOGY AND PATHOGENESIS

The disease is characterized by inflammation of the nasal mucosa. Based on its origin, rhinitis is divided into primary and secondary. Over the course of this disease, it can be acute or chronic. Based on the nature of the inflammatory process, rhinitis is diagnosed as catarrhal (mucous), croupous (fibrinous), follicular (vesicular).

The disease occurs due to irritation of the nasal mucosa by caustic gases, chemicals, infectious and invasive pathogens, as a result of intoxication, allergic manifestations, due to inhalation of hot or cold air (especially against the background of general hypothermia), as well as damage to the mucosa by foreign objects.

Factors predisposing to the onset of the disease are physical inactivity, lack of regular exercise, inadequate feeding, and vitamin A deficiency.

Secondary rhinitis is a consequence of other diseases and accompanies them.

¦ SYMPTOMS

The nasal mucosa is hyperemic and swollen. The dog sneezes, snorts, rubs its nose on objects, and sometimes coughs. Breathing is difficult, wheezing, wheezing, and is accompanied by nasal discharge, which usually dries up around the nostrils in the form of crusts. In the future, inspiratory dyspnea may appear, but with catarrhal primary rhinitis, significant changes in the condition are usually not observed. Body temperature remains within normal limits or increases by 0.5-1° C, appetite is usually preserved.

Croupous and follicular rhinitis are accompanied by swelling of the nasal mucosa and skin, accumulation of dried exudate in the form of crusts around the nostrils, an increase in general body temperature, general depression and loss of appetite. The disease is often complicated by dermatitis around the nasal openings.

¦ DIAGNOSIS AND PROGNOSIS

In differential diagnostic terms, diseases of the accessory cavities are excluded - sinusitis and frontal sinusitis, as well as infectious and invasive diseases accompanied by symptoms of rhinitis: infectious rhinotracheitis, adenovirosis, plague, etc.

Recovery from catarrhal rhinitis, as a rule, occurs after 7-10 days, and from lobar and follicular rhinitis - after 2-3 weeks in cases of a favorable course of the disease and proper treatment.

In severe cases, complications are possible in the form of sinusitis, laryngitis, pharyngitis and damage to other adjacent areas of the nasopharynx, lymphadenitis.

For adenoviruses - interferon instillation.

Symptomatic treatment; the use of expectorants is indicated.

For hyperthermic symptoms - antibiotics, sulfonamides.

Antihistamines.

¦ POSSIBLE COMPLICATIONS

Sinusitis, frontal sinusitis, otitis media.

¦ MEDICINES

DNA 0.05% 3-4 drops.

Sanorin, naphthyzin.

Penicillin, sulfadimethoxine.

Diphenhydramine, olazole.

Sinusitis, frontal sinusitis

¦ ETIOLOGY AND PATHOGENESIS

Irritation of the nasal mucosa by caustic gases and chemicals.

Infection, helminthic infestation, intoxication, allergic manifestations. Inhalation of hot or cold air, cold.

They develop as secondary diseases during rhinitis. More often they become chronic and are accompanied by green-yellow discharge with an ichorous odor.

¦ SYMPTOMS AND COURSE

The manifestation of the disease is short-term bleeding from one or both nostrils. With a unilateral inflammatory process, a characteristic turn of the dog's head to one side is observed. Increased sensitivity to palpation of the maxillary (frontal) sinuses. Percussion: unilateral or bilateral dullness. Complications: otitis media, hearing loss, transition of inflammation to the olfactory labyrinth.

Injection of antibiotic powders, solutions, ointments, liquid liniments into the cavity under local anesthesia.

¦ POSSIBLE COMPLICATIONS

¦ MEDICINES

Novocaine, trimecaine.

Penicillin on novocaine, sulfadimethoxine (powder).

Liniment of streptocide or synthomycin, streptocide and streptomycin ointments.

Canine distemper

¦ ETIOLOGY AND PATHOGENESIS

The plague virus is related to myxoviruses. Contains ribonucleic acid. Virions have a spherical, sometimes filamentous shape, their size is 90-180 nm. The outer shell has radial branches.

Immunologically, in different geographical zones, different strains of the plague virus are homogeneous and differ only in virulence.

The virus is resistant to various physicochemical factors, but when the temperature rises to 55° C, it loses virulence within 1 hour, at 37-40° C it dies after 14 days, and at 60° C – after 30 minutes.

The plague virus disappears from the blood of a sick animal after the first symptoms of the disease appear, but remains in the tissues of the mucous membranes of the respiratory tract due to its affinity for them. Here the virulence of the virus increases sharply, it multiplies abundantly and then spreads throughout the body. There are different forms of plague: gastrointestinal, pneumonic, nervous (the most severe of all forms), and mixed.

Ultimately, the virus affects the central and peripheral nervous systems, which subsequently leads to the painful death of the animal or to serious complications in the event of a favorable outcome. If a dog has suffered the plague, it can often remain crippled for life.

¦ SYMPTOMS

The disease is hyperacute, acute and abortive. The main symptoms, common to all forms of plague, are fever, often up to 40 ° C, lethargy, fatigue, lack of appetite, purulent discharge from the nose and eyes, photophobia, dry and cracked nose and skin on the paws, diarrhea, vomiting, pneumonia, nervous disorders.

Distemper is one of the most serious diseases of dogs - an acute infectious disease caused by a virus. Spread by sick dogs. It is characterized by contagiousness, fever, damage to the nervous system, respiratory tract, and gastrointestinal tract. Puppies and young dogs are especially often affected.

The hyperacute course of plague is accompanied by a sharp increase in body temperature, complete refusal of food, coma and death of the animal after 2-3 days.

For the acute course of the plague, characteristic symptoms are loss of appetite, general depression, an increase in body temperature to 41 ° C for 10-15 days, and fatigue during work. Some dogs experience vomiting, diarrhea, and mucous discharge from the nose. After 2-3 days the temperature drops and temporary recovery occurs. However, then most often the temperature rises again, abundant mucous membranes appear, and then purulent discharge from the eyes and nose, the eyelids stick together, crusts of dried pus form on the edges of the nostrils, the nose becomes clogged with pus, the dog sneezes and rubs its nose with its paw. Gradually, the signs of the disease increase. Coughing and diarrhea appear, red spots and blisters appear on hairless areas of the skin, and dry crusts fall off. Against the background of general weakness, a complete refusal of food is noted; then signs of damage to the nervous system appear (convulsions, paralysis of some muscle groups). A characteristic symptom is paresis of the rear part of the body (the dog cannot rise), paralysis of the tail and limbs.

In puppies up to 2 months of age, plague occurs, as a rule, atypically, without pronounced symptoms (erased picture of the disease).

In case of abortive course of plague, after 1-2 days of general malaise, the animal recovers.

Although new methods of combating the plague are currently being developed, practically the only effective means are preventive vaccinations. However, dogs often get plague even after vaccinations. But for most of them, vaccinations save their lives.

Regardless of the type of vaccine, a dog develops immunity within 7-14 days. To form a more stable immunity, repeated vaccination is necessary.

Puppies are vaccinated against distemper for the first time at 7-10 weeks, and again after 3-4 weeks.

Adult dogs are vaccinated once a year throughout their lives.

Nosebleed

¦ ETIOLOGY AND PATHOGENESIS

Ruptures of the walls of the vessels of the nasal cavity due to bruises, blows, wounds, hypertension. It should be differentiated from sinusitis.

Cold lotions on the nasal area, rinsing the nasal passages with solutions of astringents.

¦ SYMPTOMS

Bloody discharge from the nose, wheezing, noisy, difficult breathing.

¦ MEDICINES

Solution of tannin, tanalbin, oak bark decoction. Calcium gluconate intramuscularly.

Otitis

¦ ETIOLOGY AND PATHOGENESIS

The dog's external auditory canal has vertical and horizontal components. At the point where the canal turns, plaque removal is difficult if its formation is increased. This determines the predisposition of dogs to the development of inflammatory processes in this area.

Otitis usually begins with an increase in the formation of ear “wax”. This occurs in response to some kind of irritation. The most common causes of otitis media are allergic skin manifestations and foreign bodies (such as cereal awns); Ear mites (otodectosis) may also be noted. In poodles and schnauzers, the disease in question is caused by the growth of hair deep in the ear canal.

Increased moisture in the wax of the ear canal causes intense bacterial growth, which results in an inflammatory reaction. Subsequently, the wax mixes with the resulting pus, clogging the canal.

Chronic otitis, as a rule, is secondary, while the primary factor is usually an allergy.

¦ SYMPTOMS

The behavior of a dog with otitis media is quite typical. The animal shakes its head and tries to rub its ears on the floor and furniture. When the inflammatory process moves to the middle ear, a special tilt of the sick dog’s head is observed, vestibular disorders and unusual eye movements may appear. Possible unilateral hearing loss.

Most inflammations of the auricle are easily identified and can be treated using standard antiseptics. If there is increased formation of ear wax, the ear canal is cleaned and treated with antiseptics. Sometimes additional examination and treatment of the external auditory canal along its entire length is necessary. When performing this procedure, weak sedation with neuroleptics (chlorpromazine, acetylpromazine) is recommended, since the treatment is associated with unpleasant and even painful sensations in patients. The use of neuroleptic drugs in this case is also necessary to prevent instrumental injuries to the ear canal in cases of unexpected jerks by the dog.

Otitis media can become chronic in animals that have not received proper treatment, or when the disease recurs after treatment is stopped. In this case, cultures of the contents of the auricle are carried out, pathogens and their sensitivity to antibiotics are determined. Next, therapy is carried out using selected drugs and regular cleaning and treatment of the ears with antiseptics. At the same time, the causes of relapse of the inflammatory process should be identified. In most cases, the allergic nature of the phenomenon is confirmed.

In chronic otitis media, so-called crypts form along the ear canal. Their appearance is due to the growth of scar tissue in the canal cavity. As a result, cleaning and drainage of the purulent contents of the canal become difficult. In this case, they resort to surgical intervention.

If a pseudomonal infection is detected, otitis media can be treated with quinolones. Features of therapy include the appointment of especially high doses of these drugs: if enroxil is used in inadequate quantities, pseudomona will become resistant to it. Classic antimicrobial agents are also used - silver preparations - protargol and collargol.

¦ POSSIBLE COMPLICATIONS

During intense scratching of the ear, the dog can damage the vessels in its wall. This leads to the formation of a cavity in the tissue of the outer ear with condensation of blood and lymph collected in it - an auricular hematoma.

¦ MEDICINES

Instillation of furatsilin - 0.02% alcohol solution, hydrogen peroxide - 3%.

Bicillin-3, bicillin-5.

Penicillin, sulfadimethoxine. Enroxil. Diphenhydramine, olazole. Protargol, collargol.

Laryngitis

Inflammation of the mucous membrane of the larynx is called laryngitis. The disease occurs mainly in the cold season.

Laryngitis can be acute or chronic in course, primary or secondary in origin. Based on the nature of inflammation, catarrhal and croupous forms are distinguished.

¦ ETIOLOGY AND PATHOGENESIS

Primary laryngitis is usually a consequence of poor maintenance and feeding of the dog. The direct cause of the disease can be hypothermia, drafts, irritation of the mucous membrane of the larynx when drinking cold or hot water, inhaling irritating gases, dust, certain medications, and consuming frozen foods. Predisposing factors are low general resistance to adverse factors, pampering and lack of exercise.

Secondary laryngitis develops as complications of certain infections, when inflammation spreads to the mucous membrane of the larynx from the nasal cavity, and so on.

¦ SYMPTOMS

The main signs of acute catarrhal laryngitis are cough, narrowing of the lumen and inflammatory swelling of the larynx.

At the onset of the disease, inspiratory shortness of breath, a dry, sharp, jerky and very painful cough, which is replaced by a wet, prolonged and painless cough, are noticeable.

When inhaling cold or dusty air, taking food and water, especially cold ones, coughing attacks intensify and can provoke vomiting. Breathing is difficult, wheezing can be heard on auscultation of the chest. Palpation of the larynx area is painful (restless behavior of the animal).

Croupous laryngitis is characterized by severe depression of the sick dog, a rapid increase in body temperature to 40-41 ° C, and fibrillary twitching of the muscles. Breathing is rapid and difficult. Visible mucous membranes are cyanotic, submandibular lymph nodes are enlarged. Palpation of the larynx reveals its swelling and a sharp increase in sensitivity. When auscultating the chest, especially during inspiration, various types of wheezing are heard.

¦ DIAGNOSIS

In differential diagnosis, first of all, based on the results of palpation, percussion and auscultation, damage to the trachea, bronchi and lungs is excluded (in difficult cases, X-ray examination is recommended), as well as infectious diseases - such as plague, adenovirosis, leukemia and others.

Eliminating the cause. Warming alcohol compress on the larynx area. Vitamin therapy, antibiotics, antitussives.

¦ POSSIBLE COMPLICATIONS

The disease can be complicated by tracheitis and occur in the form of laryngotracheitis.

¦ MEDICINES

Ascorbic acid.

Bicillin-3, bicillin-5, penicillin, sulfadimethoxine.

Codeine, norsulfazole.

Cordiamine, caffeine, digalen-neo. Diacarb.

Bronchitis

Bronchitis is called inflammation of the mucous membrane and submucosal tissue of the bronchi. There are macro- and microbronchitis. In the first case, the inflammatory process is localized in the large bronchi, but when the disease spreads to the small bronchi, it is microbronchitis. If inflammation spreads along the entire bronchial tree, bronchitis is called diffuse. Diffuse bronchitis in dogs is quite common. According to the nature of the inflammatory exudate, bronchitis is catarrhal, fibrinous, purulent, putrefactive and hemorrhagic; by origin – primary and secondary; according to the course - acute and chronic.

¦ ETIOLOGY AND PATHOGENESIS

Primary bronchitis begins due to a cold. The cause of the disease is hypothermia of the animal when swimming in a cold pond, lying on cold and damp ground, prolonged exposure to rain, walking in cold and damp weather, long walks in severe frost and wind. The development of primary bronchitis is promoted by a lack of vitamins A, C and group B in the diet, irritation of the mucous membrane when inhaling smoke, dust, hot and cold air. At home, a dog can catch a cold if there is a draft in the room.

Secondary bronchitis occurs against the background of infectious diseases - plague, rhinotracheitis, adenovirosis, as well as some non-contagious ones - laryngitis, tracheitis, pleurisy, pneumonia, hypovitaminosis A.

If treatment of acute bronchitis is ineffective, the process may become chronic.

¦ SYMPTOMS

In acute bronchitis, the dog’s general condition is satisfactory or slightly depressed, appetite is often reduced, temperature fluctuates at the upper limits of normal or is increased by 0.5 ° C, and pulse is increased.

A characteristic symptom of bronchitis is bouts of frequent coughing. At first it is dry and painful, but after 3-5 days, with a favorable course, it becomes moist, dull and painless. During auscultation, hard vesicular breathing, dry rales (in the first days of bronchitis), small or large bubble wet rales (in subsequent days) are recorded. First, thick and then liquid exudate is released from the nasal openings. Percussion of the chest reveals no changes. Blood tests show neutrophilic leukocytosis with a nuclear shift to the left, a decrease in the acid capacity of the blood serum, and a high level of ESR.

With microbronchitis, body temperature rises by 1-2° C, the pulse quickens, and mixed shortness of breath intensifies. Auscultation in the affected areas reveals fine rales.

With chronic bronchitis, the disease becomes protracted, periods of improvement and remission are recorded. There is a gradual emaciation of the animal, pallor of the mucous membranes. The wheezing is dry, whistling, and exhalation shortness of breath increases. The cough is dry, mainly in the morning. X-ray examination shows no changes in the pulmonary field, however, in chronic bronchitis, the presence of areas of pulmonary emphysema and increased bronchial pattern are revealed.

Eosinophilia and monocytosis are possible in the leukogram.

If the causes of the disease are eliminated and treatment is started in a timely manner, bronchitis proceeds favorably, the dog recovers within 7-10 days.

¦ DIAGNOSIS

The diagnosis is made taking into account anamnestic data and clinical signs, laboratory and radiological studies.

In differential diagnostic terms, infectious (rinotracheitis, parainfluenza, plague, adenovirosis) and invasive (ascariasis, coccidiosis) diseases are excluded first of all. For this purpose, epizootological, microbiological, virological and other studies are used.

¦ TREATMENT

First of all, it is necessary to create conditions for the sick animal that exclude the possibility of hypothermia or overheating of its body. In the first days of illness, expectorants, antibiotics, vitamins, and sulfonamides are prescribed to overcome a dry and painful cough. Warming procedures on the chest are indicated.

¦ POSSIBLE COMPLICATIONS

If the outcome is unfavorable, the disease becomes chronic or may be complicated by bronchopneumonia and emphysema. The subsequent transition of the inflammatory process from the bronchi to the lungs is accompanied by a sharp deterioration in the general condition of the animal and an increase in body temperature.

Chronic bronchitis is very often complicated by bronchiectasis, bronchial asthma, atelectasis and emphysema.

¦ MEDICINES

Thermopsis, marshmallow root, and sodium bicarbonate are prescribed as expectorants.

Bronchial spasms are relieved with aminophylline, isadrine, and ephedrine.

Antibiotics: penicillin, bicillin-3, -5, streptomycin.

Vitamins: A, E, C.

Enroxil 1 ml per 10 kg of dog weight in the form of a 5% solution subcutaneously. Papaverine hydrochloride.

Bronchopneumonia

Bronchopneumonia, also called “catarrhal pneumonia”, “focal pneumonia”, “nonspecific pneumonia”, is characterized by inflammation of the bronchi and lobes of the lungs, which is accompanied by the formation of catarrhal exudate and filling the lumen of the bronchi and alveoli with it. Most often, young predators suffer from this type of pneumonia.

¦ ETIOLOGY

Bronchopneumonia in dogs is a disease of a polyetiological nature. Non-specific factors such as hypothermia of the animal while walking, swimming in a pond with cold water, drafts, high humidity, microbial and viral pollution of indoor air, frequent exposure to cement floors, drinking cold water, feeding ice cream are very significant in its occurrence. food, etc.

Poor nutrition, lack of vitamins in the diet, especially A and C, lack of ultraviolet radiation, and poor hardening of dogs contribute to the occurrence of bronchopneumonia. These factors lead to a decrease in the body’s natural resistance, against the background of which an association of nonspecific viruses and opportunistic microflora of the respiratory tract occurs (pneumococci, streptococci and staphylococci, salmonella, mycoplasma, adenoviruses). The total number of types of microorganisms isolated from the lungs during bronchopneumonia ranges from 10-60. These microorganisms cause the development of an autoinfectious process.

Secondary bronchopneumonia occurs as a complication of certain non-contagious (bronchitis, pleurisy, pericarditis, heart defects) and infectious (plague, parainfluenza, colibacillosis, adenovirosis) diseases.

¦ SYMPTOMS

Bronchopneumonia can occur in acute, subacute and chronic forms.

The first sign of the disease is general depression. A relapsing-type fever with an increase in temperature of 1-2° C, weakness, and loss of appetite (sometimes it disappears completely) is recorded. On the 2-3rd day of illness, symptoms of damage to the respiratory system are clearly visible. Main symptoms: cough, increased strained breathing and shortness of breath, serous catarrhal or catarrhal discharge from the nasal openings, hard vesicular breathing, wheezing in the bronchi and lungs, initially dry and then wet. In large dogs, percussion reveals areas of dullness in the area of ​​the anterior lobes of the lungs.

The subacute form is characterized by a longer course. The illness can last 2-4 weeks. The type of fever is intermittent.

The patient's condition improves and deteriorates. Clinical symptoms from the respiratory system differ from those in the acute course. Paroxysmal cough, purulent serous-mucous discharge from the nose. Patients lose weight and are stunted in growth and development.

X-ray examination in the cranial and cardiac lobes of the lungs reveals homogeneous foci of shading of moderate density, blurring of the pulmonary field, veiling of the anterior border of the heart, unclear contours of the bronchial tree in the initial stages of bronchopneumonia. The contours of the ribs in the areas of pneumonic lesions are clearly visible.

The chronic form is more common in puppies and older dogs. The animals become emaciated, the fur becomes dull, the elasticity of the skin decreases, and dandruff is found on its surface. The cough is paroxysmal, prolonged, painful. Most of the lungs are involved in the inflammatory process; alveolar lung tissue is replaced by connective tissue.

Emphysematous areas gradually appear. An increase in symptoms of cardiovascular failure, dysfunction of the gastrointestinal tract, liver, kidneys, the occurrence of anemia, and skin diseases are noted.

A blood test reveals neutrophilic leukocytosis with a shift to the left, eosinopenia, monocytosis, lymphopenia, a decrease in catalase activity and reserve alkalinity of the blood, a relative decrease in albumin and an increase in globulin fractions, an increase in ESR, a decrease in the saturation of hemoglobin in arterial blood with oxygen.

In the chronic course, radiography reveals dense foci of shading in the area of ​​the apical and cardiac lobes, the anterior border of the heart is invisible in most cases, the contours of the ribs in the affected areas are not clearly visible. In the dorsal areas of the lung adjacent to the spine, areas of pulmonary emphysema and increased contours of the bronchial pattern are visible.

¦ DIAGNOSIS

If necessary, to clarify the diagnosis, a biopsy of the affected areas of the lungs, bronchography, bronchophotography, examination of tracheal mucus, nasal discharge and other methods are used.

In the differential diagnostic relation, infectious diseases (pasteurellosis, salmonellosis, plague, rhinotracheitis, mycoplasmosis), as well as some non-communicable diseases - bronchitis, laryngitis, pleurisy, pulmonary edema, are excluded.

Antibiotics, cephalosporins, sulfonamides.

Vitamins, antioxidants. Bronchodilators.

¦ MEDICINES

Penicillin, bicillin-3, -5, streptomycin, gentamicin.

Sulfonamides: streptocide, sulfadimethaxine, sulfalene, sulfazine.

Eufillin, isadrine, ephedrine.

Vitamins: A, E, C.

Emphysema

The disease is characterized by pathological expansion of the lungs with an increase in their volume. There are alveolar and interstitial emphysema. In the first case, changes in the lungs occur due to stretching of the alveolar tissue. With interstitial pulmonary emphysema, an increase in lung volume is observed due to the penetration of air into the interlobular connective tissue.

¦ ETIOLOGY

Acute alveolar emphysema occurs with frequent and intense breathing as a result of overstrain of the alveolar tissue (during long runs in sports competitions, with excessive use of sled dogs and hunting dogs). Chronic alveolar emphysema develops as a continuation of acute. Allergic factors and hereditary predisposition play a significant role in the occurrence of alveolar emphysema (purebreds are more often affected).

The cause of interstitial emphysema is the penetration of air into the interlobular connective tissue when the walls of the bronchi and caverns rupture during excessive physical exertion.

¦ SYMPTOMS

Animals with acute alveolar emphysema get tired very quickly, even with minor physical exertion. Characteristic signs are severe shortness of breath, sudden movements of the costal walls and abdominals during breathing, dilated nostrils, sometimes breathing is accompanied by groans, dogs breathe with their mouths open. Auscultation reveals hard vesicular breathing in the anterior parts of the lungs, the percussion sound of the pulmonary field is boxy and loud. A characteristic symptom is a displacement of the caudal border of the lungs back by 1-2 ribs, in some cases this border extends beyond the last rib. The temperature is normal, in rare cases subfebrile. Many patients experience a compensatory increase in cardiac activity: increased heart rate, increased heart sounds. In the case of a favorable course of the disease, after removing physical stress and giving the animal rest, the symptoms of acute alveolar emphysema disappear within a few days.

With chronic alveolar emphysema, the characteristic expiratory shortness of breath intensifies over time. The exhalation is made tense and elongated, and it is carried out in two phases: first, the chest quickly descends, then, after a short period of time, a powerful contraction of the abdominal wall occurs. The exhaled stream of air is weak, although breathing is very intense. Upon percussion, a loud box sound is clearly detected throughout the pulmonary field; the percussion border of the lungs is pushed back 1-4 intercostal spaces. Auscultation reveals weakened vesicular breathing, weakened cardiac impulse, increased diastolic heart sounds and increased heart rate. Symptoms of shortness of breath are greatly aggravated by physical activity.

Interstitial emphysema is characterized by an acute and rapid course. The penetration of air into the interlobular connective tissue of the animal sharply worsens its general condition, signs of asphyxia increase: progressive shortness of breath, cyanosis of the mucous membranes, cardiovascular failure. Auscultation reveals fine rales and crepitus in the lungs. Crepitation of air bubbles (subcutaneous emphysema) is found under the skin, usually in the neck, chest, and sometimes the croup and back.

X-ray studies show clearing of the pulmonary field in emphysematous areas of the lungs, increased bronchial pattern, and backward displacement of the dome of the diaphragm. In dogs, a compensatory increase in the number of red blood cells and the amount of hemoglobin in the blood is often noted.

¦ DIAGNOSIS

The differential diagnosis excludes pneumonia, pleurisy, hydrothorax, hemothorax, pneumothorax.

Pleurisy

Inflammation of the pleura of the lungs in dogs is recorded quite rarely. According to the course, pleurisy is divided into acute and chronic, according to localization - into limited and diffuse, and depending on the nature of the inflammatory process - into exudative (effusion) and dry. Exudative pleurisy can be serous, serous-fibrinous, purulent and putrefactive. With purulent-putrefactive pleurisy, due to the decomposition of the exudate, fluid accumulates in the pleural cavity (hydropneumothorax).

¦ ETIOLOGY

Pleurisy as an independent disease is a consequence of a cold or infection due to penetrating wounds of the chest wall; It is extremely rare to occur initially. In most cases, it develops as a secondary disease with complications of pneumonia, pneumothorax, peritonitis, rib caries, septicemia, some infections and other diseases, if the animal has not fully recovered and etiological factors continue to operate.

¦ SYMPTOMS

In dogs, the disease is usually acute, less often chronic. The main symptoms are general depression, weakness, lack of appetite, decreased mobility and performance. The temperature rises by 1-1.5° C. Respiratory movements are frequent and intense, mixed shortness of breath and abdominal breathing. For unilateral pleurisy, a characteristic symptom is asymmetry of the respiratory movements of the chest. Animals lie down less often. In case of dry pleurisy, they are usually placed on the healthy side, and in case of wet pleurisy, on the affected side.

With dry pleurisy, a painful reaction is expressed during palpation and percussion of the intercostal spaces. With effusion pleurisy, pain is usually not detected.

Auscultation establishes pleural friction sounds and synchronous respiratory movements.

In the initial stages of development of effusion pleurisy, along with pleural friction noise, splashing noises can also be detected. Subsequently, the friction noise disappears; on the affected side, weakened heart sounds and respiratory sounds are heard, and on the healthy side, increased vesicular breathing is heard. There is a dullness of the lung area with a horizontal upper border, which does not move when the animal’s body position changes. An increase in symptoms of respiratory and heart failure is noted.

¦ DIAGNOSIS

X-ray examination of effusion pleurisy shows shading of the lower parts of the pulmonary field, the upper horizontal line fluctuates during respiratory movements. To clarify the diagnosis, it is recommended to perform a puncture of the pleural cavity.

The differential diagnosis excludes hydrothorax, hemothorax, pericarditis, rheumatism, hydremia, lobar pneumonia, and chronic nephritis. With hydrothorax there is no pain in the chest wall, the temperature is normal.

After a preliminary diagnosis has been made, it is necessary to prevent exudate from leaking into the pleural cavity by administering intravenous calcium chloride or calcium gluconate.

For preventive purposes, antibiotics are indicated to prevent infection from entering the pleural cavity. To remove water from the body - diuretics. The use of drugs that support cardiac activity is recommended.

Physiotherapy, the Sollux apparatus and warm covering are indicated.

¦ MEDICINES

Among antibacterial drugs, it is recommended to use penicillin, bicilin-3, bicilin-5, dihydrostreptomecin sulfate. Use methyl salicylate to rub into the skin. Orally – oletethrin, olendamycin. Intramuscular streptomycin sulfate. Erythromycin. Norsulfazole.

Heart remedies: camphor and caffeine.

Enroxil 5% 1 ml per 10 kg of animal weight, administered subcutaneously.

Hydrothorax

Hydrothorax, or chest dropsy, is a disease that occurs with the accumulation of transudate in the pleural cavity.

¦ ETIOLOGY

In most cases, hydrothorax is a symptom of general dropsy of the body or cardiovascular failure, a consequence of myocarditis, myocardosis, and decompensated heart valve defects. The cause of the disease may be local circulatory or lymphatic disorders due to compression of blood vessels or the thoracic lymphatic duct (for example, by tumors). The occurrence of hydrothorax is promoted by hydremia of body tissues, hypovitaminosis C and K, anemia, intoxication, which increases the permeability of vascular walls.

¦ SYMPTOMS

General weakness, symptoms of cardiovascular failure and cyanosis of the mucous membranes are noted, mixed shortness of breath progresses against the background of normal or subfibrile body temperature of the animal. Palpation of the chest wall is painless. When changing posture, the upper border of the dullness remains horizontal. There may be periods of improvement or deterioration during the course of the disease.

¦ DIAGNOSIS

In differential diagnostic terms, pleurisy is excluded. Transudate with hydrothorax, unlike exudate with pleurisy, is transparent and of lower density.

¦ TREATMENT

As a rule, therapy is ineffective. Patients are given rest, freed from exercise and training, and fluid intake is limited.

It is recommended to prescribe cardiac medications, diuretics, and intravenous administration of hypertonic solutions of glucose and calcium chloride. To facilitate breathing, 200-300 ml of transudate is released once every 2-3 days by puncture of the pleural cavity.

The structure of the dog’s cardiovascular system and its features

The dog's heart lies almost horizontally from the 3rd to 7th ribs, wide, short with a blunt apex. The right atrium contains the vena cava and the right azygos vein. Four pulmonary organs flow into the left atrium. The bicuspid atrioventricular valve has an underdeveloped third leaflet, and the tricuspid valve has a fourth. In the fibrous ring of the aorta there are three small cartilages, calcified in old animals.

The brachiocephalic and left subclavian arteries depart from the aortic arch. The brachiocephalic artery branches into the left and right common carotid arteries and passes into the right subclavian artery. The subclavian arteries branch.

Each carotid artery is divided into an external one, which supplies blood to the head, and a weak internal one.

The arteries and veins of the limbs and trunk are similar to those of other domestic placental animals.

The composition, structure and functions of the lymphatic system are the same as those of other domestic mammals.

Diseases of the cardiovascular system

The main factors that should be based on when diagnosing diseases of the cardiovascular system:

– strength, frequency and rhythm of heart contractions;

– presence of cardiac murmurs;

– state of the cardiovascular system and blood according to the color of the mucous membranes;

– presence of edema.

Heart murmurs are sounds heard in the region of the heart during heart disease.

Extrasystole

Hypoxia and epicardial myocardial damage

Complete gastric block

Myocardial infarction, bundle branch block

Cardiac ischemia

ELECTROCARDIOGRAMS OF DOGS WITH MYOCARDIAL DISEASES

Myocardosis

Myocardosis is a disease of the myocardium of a non-inflammatory nature, characterized by the presence of degenerative processes in it.

¦ ETIOLOGY

The cause of this disease may be disturbances in protein, fat, carbohydrate, mineral and vitamin metabolism (unbalanced feeding); intoxication in chronic diseases. Often myocardosis is a consequence of previous myocarditis, endocarditis, pneumonia and other diseases.

¦ SYMPTOMS

Symptoms are determined by the stages of development of the disease and its clinical forms. In mild cases, cardiovascular failure is detected only after physical activity, and in severe cases, even at rest.

The course of the disease in all cases is accompanied by general weakness of the animal, decreased appetite and muscle tone, and peripheral circulatory disorders (venous blood pressure increases and arterial blood pressure decreases). General symptoms also include decreased skin elasticity, swelling on the body, shortness of breath, cyanosis of visible mucous membranes and skin, disturbances in the frequency and rhythm of heart contractions (pulse rate is increased, atrioventricular block and bundle branch block are characteristic).

Myocardial dystrophy without pronounced destructive changes in the myocardium is characterized by the following symptoms: slight increase in pulse rate, weakening of the cardiac impulse, strengthening, splitting or bifurcation of the first heart sound with a weakening of the second sound; possible disturbance of cardiac conduction function; blood flow is slow.

At the beginning of the development of myocardial dystrophy, the electrocardiogram shows expansion, deformation of the T wave and a slight displacement of the ST segment; subsequently, a more pronounced displacement of the ST segment relative to the isoelectric line occurs, a change in the PQ and QT intervals, and a decrease in ECG waves (especially the QRS complex).

Myocardial dystrophy with pronounced destructive changes in the myocardium is manifested by more pronounced symptoms.

The electrocardiogram shows low wave voltage, pronounced prolongation of the PQ and QT intervals, deformation and expansion of the QRS complex.

Elimination of etiological factors that caused myocardosis. Providing patients with rest and peace.

It is necessary to balance the feed ration by introducing vegetables, fruits and dairy feed.

The use of glucose, caffeine, ascorbic acid in high doses, camphor, sulfacamphocaine, and cordiamine is indicated.

No less effective for myocardosis are anabolic agents that improve biochemical and bioenergetic processes in the heart muscle.

If the functions of other organs and systems are impaired, appropriate symptomatic treatment is carried out.

¦ MEDICINES

Glucose, caffeine, ascorbic acid, camphor, sulfacamphocaine, cordiamine.

If there is a sharp drop in blood pressure, adrenaline is recommended.

Thiamine, riboflavin, pyridoxine, cocarboxylase, potassium orotate, adenosine triphosphoric acid (ATP), cytochrome-C, panangin, riboxin.

Myocarditis

Myocarditis is an inflammation of the heart muscle with the development of exudative-proliferative and degenerative-necrotic changes in the interstitial tissue of the heart muscle. The disease is accompanied by increased excitability and decreased contractility of the myocardium.

¦ ETIOLOGY AND PATHOGENESIS

It occurs as an independent disease extremely rarely. Most often it is a complication of infectious diseases (plague, parvovirus enteritis, infectious hepatitis, rabies, leptospirosis, staphylococcosis and other diseases), as well as intoxication with poisons of exogenous and endogenous origin, products of purulent tissue decay.

¦ SYMPTOMS

In addition to the manifestation of signs of the underlying disease, cardiovascular insufficiency is strongly expressed. Depression, decreased or lack of appetite, and increased temperature are possible.

The initial period of development of acute myocarditis is characterized by the following symptoms: tachycardia, extrasystole, pain in the heart area, a large wave full pulse, increased heart sounds, especially the first, increased, and sometimes pounding heartbeat. Blood pressure is increased.

The electrocardiogram shows a sharp increase in the P, R, and especially T waves, a shortening of the PQ and QT intervals, and a shift in the ST segment. These changes describe the intense, increased work of the heart.

In the second period of myocarditis, the main symptoms of cardiovascular failure often appear: shortness of breath, cyanosis, edema, severe heart rhythm disturbances. The latter mainly manifest themselves in the form of ventricular extrasystole, atrial fibrillation and flutter. Rhythm disturbances are possible in the form of partial or complete atrioventricular block, bundle branch block. Pulse filling is weak. The heartbeat weakens. The first tone is strengthened, can be bifurcated or decoupled, the second tone is weakened. With deep destructive changes in the myocardium, a gallop rhythm, a sharp weakening and deafness of both tones are recorded.

In the second period of the disease, functional endocardial murmurs are observed. There is a tendency for arterial blood pressure to fall and venous blood pressure to increase.

The ECG shows a decrease in the waves of the QRS complex (the QRS becomes wider and deformed), the T wave becomes wider, the PQ and QT intervals lengthen, the ST segment is shifted.

The functions of other organs and systems of the body are disrupted, as evidenced by the appearance of shortness of breath, edema, cyanosis or yellowness of the mucous membranes and skin, decreased diuresis, and developing disorders of the digestive processes. In all cases, the nervous system suffers.

Blood examination reveals neutrophilic leukocytosis with regenerative or degenerative nuclear shift.

Eliminate the cause (acute infection) that caused myocarditis. Peace, absence of unnecessary irritation, movement and noise.

Vegetables and fruits, lean meat, sugar or glucose, and lactic acid products are added to the diet of sick animals. Feed and water the dog often, in small portions. Monitor your intestines and avoid constipation.

Antibiotics and sulfonamides are used to treat myocarditis.

In the first period of the disease, one should not rush to use cardiac medications that enhance cardiac activity (digitalis). Otherwise, cardiac paralysis may occur. With severe myocardial excitability, the use of valerian tincture, sometimes peony tincture and camphor preparations is indicated. Cordiamine is administered intravenously, subcutaneously or intramuscularly in 0.2-1 ml doses.

With the development of the disease and in chronic cases, glucose, Actovegin, and caffeine are recommended to alleviate the symptoms of cardiovascular failure.

For swelling of the subcutaneous tissue - theobromine and gluconate or calcium chloride.

To weaken the sensitization of the heart muscle, antihistamines are used: diphenhydramine, tavegil, suprastin, as well as aspirin, amidopyrine.

Hormonal drugs have the greatest desensitizing effect: cortisone, hydrocortisone, prednisolone and their analogues.

¦ POSSIBLE COMPLICATIONS

Myocarditis often ends with myocardial degeneration and myocardial fibrosis.

¦ MEDICINES

Antibiotics: ampicillin, ampiox, claforan, reflin, kefzol.

Sulfonamides: sulfadimezin, sulfalene, biseptol.

Valerian tincture, sometimes peony tincture, camphor preparations.

Cordiamin.

Glucose, Actovegin, caffeine.

Theobromine, calcium gluconate or calcium chloride. Diphenhydramine, tavegil, suprastin.

Aspirin, amidopyrine.

Cortisone, hydrocortisone, prednisolone.

Cocarboxylase, cordarone, procainamide.

Endocarditis

Endocarditis is inflammation of the inner lining of the heart. According to the localization of the inflammatory process, the disease can be valvular and parietal, according to the nature of the pathology - warty and ulcerative, and according to its course - acute and chronic.

¦ ETIOLOGY AND PATHOGENESIS

Endocarditis in dogs and cats is more often observed as a secondary disease of an infectious-toxic nature (with streptococcosis, colibacillosis, pasteurellosis, plague, parvovirus enteritis, leptospirosis and other infections). Inflammation of the endocardium can also occur due to the transition of the inflammatory process from the myocardium. The following symptoms predispose to the disease.

¦ SYMPTOMS

At the beginning of its development, acute endocarditis is described by the following main symptoms: severe depression up to the development of a soporous state; appetite is reduced or completely absent; body temperature is increased to 40 ° C, especially with ulcerative endocarditis; pulse large, full; tachycardia, cardiac impulse and heart sounds are increased, especially the first one; Endocardial murmurs are heard.

The manifestation of the disease depends on the nature of the underlying (primary) disease and the clinical form of endocarditis. Remitting fever and increasing symptoms of cardiovascular failure are recorded. The pulse, initially large and full, becomes small and weakly filled as the disease develops, heart sounds weaken, become muffled and are accompanied by endocardial murmurs. The development of ulcerative endocarditis is characterized by a change in the intensity of endocardial murmurs, which are more constant with warty endocarditis.

An electrocardiogram in acute endocarditis records an increase in the voltage of the P, R, T waves, shortening of the PQ and QT intervals, displacement and deformation of the ST segment. Extrasystoles may appear. Blood pressure is usually elevated.

Blood tests reveal neutrophilic leukocytosis and sometimes septic changes.

The prognosis for endocarditis is usually unfavorable.

Treatment of the primary disease. At the beginning of the development of acute endocarditis, the sick animal is provided with complete rest and silence.

Antibiotics and sulfonamides.

Salicylic drugs, antiallergic therapy, as well as glucocorticoids.

In the future, camphor, sulfocamphocaine, cordiamine, solutions of glucose and ascorbic acid, B vitamins, isotonic sodium chloride solution, caffeine, adonis and lily of the valley preparations are used.

¦ POSSIBLE COMPLICATIONS

Damage to the heart valve apparatus causes serious circulatory disorders in the body. This affects the functioning of the lungs, gastrointestinal tract, liver, and kidneys. With ulcerative endocarditis, a concomitant disease is vascular embolism, and therefore, hemorrhages may appear on visible mucous membranes, skin, damage to the meninges, and brain.

¦ MEDICINES

Claforan, kefzol, cefamezine, longacef, sodium or potassium benzylpenicillin, levomecithin.

Sulfadimezin, sulfalene, biseptol, norsulfazole, sulfadimethoxine, streptocide. Diphenhydramine, tavegil, suprastin, pipolfen, fenkarol. Metypred, prednisolone, hydrocortisone.

Camphor, glucose, and saline solution are administered intravenously by drip. Doses of adonis and lily of the valley preparations are the same as for the treatment of myocardosis.

Traditionally, 4 D therapy is used to treat heart disease. Depending on the disease, therapy may include one of the “Ds” or all four: a low-sodium diet; diuretics; dilators and digoxin.

Heart attack

A heart attack is called ischemic necrosis of the myocardium caused by an acute discrepancy between the coronary blood flow and the needs of the heart muscle.

¦ CURRENT

During a heart attack, 5 myocardial periods are clinically distinguished. Prodromal (pre-infarction) lasts from several hours to one month. He may be missing. The most acute period is the phase from the onset of severe myocardial ischemia to the appearance of signs of necrosis. The acute period is characterized by the formation of necrosis and myomalacia and lasts from 2 to 14 days. During the subacute period, the initial processes of scar organization are completed and necrotic tissue is replaced by granulation tissue. These processes predominate up to 4-8 weeks from the onset of the disease. The last, post-infarction period is characterized by an increase in scar density and maximum adaptation of the myocardium to new operating conditions. The duration of this stage is up to 3-6 months from the onset of a heart attack.

¦ SYMPTOMS

In the pre-infarction period, unstable angina is noted, which is not an independent syndrome, but only the first symptom in time.

In the most acute period, the dog experiences extremely intense pain in the area of ​​the left elbow. The pain is not relieved by nitroglycerin, is accompanied by fear, excitement and is wave-like. This continues for several hours and even days. When examining the animal, bradycardia or tachycardia and arrhythmia, pallor of the skin and visible mucous membranes are noted. During percussion and auscultation, an expansion of the border of the heart to the left and a weakening of 1 tone or both tones are recorded.

In the acute period, the pain disappears. Symptoms of heart failure persist.

In the subacute period, rhythm disturbance may persist, tachycardia and systolic murmur disappear.

The electrocardiogram reflects the characteristic dynamics of changes in the ST segment or T wave that persist for more than a day: a shift of the ST segment above the isoline, followed by the formation of a negative T wave and a decrease in ST. A pathological Q wave or QRS complex is formed.

Complete rest, combating shock and pain, the use of drugs that compensate for heart failure is indicated.

The diet should consist of easily digestible carbohydrates, lactic acid and fortified feed; fats, sweets and spices are excluded.

For treatment, lipostabil, glucose, anaprilin, calcium chloride mixed with glucose are widely used. Antianginal drugs have a good therapeutic effect - analgin, antipyrine, amidopyrine, baralgin, salicylic acid preparations.

To weaken the sensitization of the heart muscle, diphenhydramine, tavegil, suprastin, pipolfen are used. To prevent thromboembolic complications during myocardial infarction, heparin is administered. To improve blood supply to the myocardium, myofedrine, cytochrome C, cocarboxylase, vitamins, multivitamins and ATP are used.

¦ MEDICINES

Caffeine, camphor, lipostabil, glucose, anaprilin, calcium chloride mixed with glucose. Analgin, antipyrine, amidopyrine, baralgin, salicylic acid preparations.

Diphenhydramine, tavegil, suprastin, pipolfen. Heparin.

Myofedrin, cytochrome C, cocarboxylase, vitamins, multivitamins and ATP.

Arteriosclerosis

Arteriosclerosis is a disease accompanied by chronic changes in the walls of the arteries. This is expressed in their compaction, hardening, thickening and decreased elasticity.

Arteriosclerosis is rarely reported in dogs.

¦ ETIOLOGY AND PATHOGENESIS

The etiology of this disease has not yet been fully elucidated.

An important role is played by a decrease in the functional capacity of blood vessels as a result of the effects of mechanical and chemical irritants (toxic exogenous substances and endotoxins), especially bacterial toxins in infectious diseases, poisoning with rancid fats, overstrain of arterial walls with increased blood pressure during hard, tiring work.

Intimal arteriosclerosis is based on two processes:

degenerative-necrotic and regenerative-progressive. The first is accompanied by the disintegration of the intima into a mushy mass (atheromatosis), the second by the proliferation of connective tissue and sclerosis of the intima (sclerosis). Mainly large vessels are affected. They lose elasticity, which creates great difficulties for blood circulation. Loss of elasticity of the aortic wall prevents emptying of the left ventricle during systole and leads to its hypertrophy. The walls of the aorta itself stretch unevenly during systole and cannot contract satisfactorily during diastole. This contributes to the formation of an aortic aneurysm.

During sclerotic processes, the muscular layer of the peripheral arteries is destroyed and replaced by connective tissue, the arteries cannot change their lumen (caliber). The required blood flow to the organs is disrupted.

At the beginning of the process, small white or pale yellowish plaques form on the intima of the arteries (at the bends and places of branching of the vessels). In the affected areas, there is a proliferation of connective tissue and elastic fibers, slight fatty degeneration and calcification. Due to loss of elasticity, the arterial wall bulges, forming aneurysms over time.

¦ SYMPTOMS

General weakness, difficulty breathing during movement, development of left ventricular hypertrophy or thrombosis and embolism for no apparent reason.

General arteriosclerosis is established by altered peripheral arteries. Their walls are inactive and unevenly hard; the pulse may be sluggish (myocarditis) or strong (left ventricular hypertrophy). Blood pressure is increased. The second aortic sound is increased. With a sluggish pulse, the pulse wave slowly rises and slowly falls. Aortic aneurysm is often observed.

The disease usually progresses.

¦ POSSIBLE COMPLICATIONS

With sclerosis of the coronary vessels, the nutrition of the heart is disrupted, myocarditis develops, and symptoms of cardiac weakness appear. With sclerosis of the vessels of the extremities, movement is disrupted. Due to insufficient nutrition of the brain tissue, brain phenomena appear - a depressed state, sometimes epileptiform or apoplexiform seizures.

Heart defects

Defects are diseases associated with deformation of the heart valves and manifested by circulatory disorders as a result of their improper functioning.

Congenital defects account for about 15% of heart disease in dogs. They are usually caused by genetic traits. Many dogs with severe congenital heart defects die within the first year of life.

Acquired heart valve disease is age-related and occurs in 1/3 of dogs over 12 years of age. The valves degenerate over time and some blood leaks back. This increases the stress on the affected heart valve.

Due to the proliferation of connective tissue on the valve, it thickens. The result of this is a violation of the free flow of blood. Part of the blood returns through a loosely closed hole into the overlying cavity of the heart, stretches it, and vibration of the edges of the deformed valve occurs (endocardial murmur).

The correct intracardiac blood circulation is disrupted and causes circulatory disorders throughout the body.

Insufficiency in the functioning of one or another valve can be compensated by myocardial hypertrophy in the corresponding parts of the heart. The degree of compensation depends on the development of the muscles of the hypertrophied part of the heart and the size of the valve defect. But when the heart has to contract intensely due to severe muscle tension of the animal, decompensation may again occur, that is, circulatory disorder of varying degrees.

An early sign of heart valve disease is a dry, hacking cough (mainly after training or at night).

Eight simple heart defects are differentiated, which can be combined.

Bicuspid valve insufficiency

ETIOLOGY AND PATHOGENESIS

The circulatory disorder with this defect is caused by incomplete closure of the left atrioventricular orifice.

During left ventricular systole, blood is only partially pushed into the aorta, and partially returns back to the left atrium through loosely closed bicuspid valves. The left atrium becomes full and stretched. During diastole, blood flows from it into the left ventricle. Stretching of the latter leads to reflex hypertrophy of the muscular walls of the ventricle. Hypertrophy of muscle fibers also occurs in the left atrium. But its walls are weak, so blood stagnation quickly occurs in the pulmonary circulation, an additional obstacle is created for the work of the right ventricle and hypertrophy of its muscles develops.

¦ SYMPTOMS

The first heart sound is weakened, bifurcated, the second is intensified. The dullness is extended posteriorly. During decompensation, a weak filling pulse of a small wave is heard. Auscultation reveals a systolic endocardial murmur at the site of the projection of the left atrioventricular valves in the 5th intercostal space. With decompensation of the defect, cyanosis of the mucous membranes and mixed shortness of breath appear.

¦ POSSIBLE COMPLICATIONS

This defect is well compensated, but the pulmonary circulation remains overflowing with blood. Due to an increase in blood pressure in the lungs, breathing becomes more frequent, bronchial catarrh and pulmonary sclerosis develop. With subsequent decompensation of the defect, venous congestion in the lungs increases, and pulmonary edema may occur.

Narrowing of the left atrioventricular orifice

Changes in the body of dogs are caused by circulatory disorders as a result of deformation of the valves. The movement of blood from the left atrium to the left ventricle during ventricular diastole is difficult.

¦ ETIOLOGY AND PATHOGENESIS

Thickened or compacted valves cannot recline freely during ventricular diastole and protrude into the lumen of the orifice. Blood is partially retained in the left atrium. At the beginning of diastole, blood flow from the left atrium to the ventricle is slow. Before ventricular systole, contraction of the left atrium sharply accelerates it, causing increased vibration of the deformed valves. Stretching of the atrium leads to compensatory muscle hypertrophy. With decompensation, the atrium expands, blood stagnates in the lungs, and edema develops.

¦ SYMPTOMS

Clinical symptoms include rapid breathing, cyanosis of visible mucous membranes, endocardial presystolic murmur, which is clearly audible in the lower third of the chest at the site of the projection of the left atrioventricular valves in the 5th intercostal space.

The arterial pulse is rapid, of small filling and small wave, the first heart sound is increased. Possible atrial extrasystole or atrial fibrillation. The vice is poorly compensated.

¦ POSSIBLE COMPLICATIONS

With decompensation, catarrhal inflammation of the bronchi and pulmonary edema are observed.

Tricuspid valve insufficiency

¦ ETIOLOGY AND PATHOGENESIS

This defect is associated with a defect in the closure of the tricuspid valves due to their shrinkage or perforation. During right ventricular systole, blood partially returns to the right atrium through the deformed valves.

The defect is compensated by hypertrophy of the right atrium and ventricle.

Decompensation develops quickly and is manifested by venous stagnation in the systemic circulation, especially in the portal system.

¦ SYMPTOMS AND DIAGNOSIS

The defect is diagnosed by a systolic endocardial murmur in the lower third of the chest on the right in the 4th intercostal space at the site of the projection of the right atrioventricular valves.

During decompensation, congestion in the portal vessels, kidneys and spleen, catarrhal enteritis, venous hypertension of the liver with impairment of its functions are recorded. Then venous pressure increases, the relief of the veins, and cyanosis of the mucous membranes increase.

Narrowing of the right atrioventricular orifice

¦ ETIOLOGY AND PATHOGENESIS

At the end of diastole, blood passes through a narrowed opening from the right atrium into the right ventricle, forming a murmur before ventricular systole.

Stenosis of the atrioventricular orifice causes overflow of the right atrium with blood, its stagnation in the systemic circulation, expansion and hypertrophy of the right atrium and left ventricle.

¦ SYMPTOMS

Stagnation of blood in the veins of the systemic circulation, severe congestion of the veins, cyanosis, congestive liver, dilatation of the right atrium. The first tone is clapping. The vice is poorly compensated.

Aortic valve insufficiency

¦ ETIOLOGY AND PATHOGENESIS

With this pathology, the aortic opening does not close completely due to wrinkling or perforation of the valves during ventricular diastole. Blood ejected into the aorta partially returns to the left ventricle.

Due to hypertrophy of the muscles of the left ventricle, the defect is well compensated. As a result of decompensation, blood stagnation in the pulmonary circulation increases.

¦ SYMPTOMS AND DIAGNOSIS

Large, galloping arterial pulse. It is diagnosed by the presence of diastolic endocardial murmur at the site of the projection of the aortic valves in the 4th intercostal space (under the line of the shoulder joint). The cardiac impulse on the left is increased, cardiac dullness is increased in the caudal direction. During auscultation of the heart, a weakening of both sounds is recorded.

Narrowing of the aortic opening

¦ PATHOGENESIS AND SYMPTOMS

Changes in the body of dogs are caused by stagnation of blood in the left ventricle, which leads to its hypertrophy. As blood passes through the narrowed opening of the aorta, a systolic murmur is heard at the optimal point of the aorta on the left in the 4th intercostal space.

Palpation of the cardiac region reveals trembling of the chest wall during left ventricular systole. The arterial pulse is slow and small waves.

With decompensation, the left ventricle dilates. Reduced blood flow into the aorta leads to cerebral ischemia, static ataxia and fainting are observed.

Pulmonary valve insufficiency

¦ ETIOLOGY AND PATHOGENESIS

This defect is associated with deformation (wrinkling or perforation) of the pulmonary valves. Blood during diastole partially returns to the right ventricle. Short-term compensation of the defect occurs due to hypertrophy of the right ventricle.

¦ SYMPTOMS

Decompensation is manifested by insufficient blood flow into the pulmonary vessels. An endocardial diastolic murmur is heard at the site of the projection of the pulmonary artery valves on the left in the 3rd intercostal space (near the ends of the ribs). Cyanosis of the mucous membranes and rapid breathing when the dog moves are recorded.

Narrowing of the pulmonary artery opening

¦ ETIOLOGY AND PATHOGENESIS

The cause of the disease is thickening and low mobility of the valves that close the openings of the pulmonary artery. The release of the right ventricle during systole is difficult, and an insufficient amount of blood enters the pulmonary vessels.

¦ SYMPTOMS AND DIAGNOSIS

This pathology in most cases is diagnosed by systolic endocardial murmur at the site of the left projection of the pulmonary valves in the third intercostal space at the ends of the ribs, weakening of the second heart sound.

Differential diagnosis, prognosis and treatment of heart defects

Murmurs arising from heart defects are of particular importance for making a diagnosis.

Electrocardiography plays a supporting role.

In the differential diagnosis, it is necessary to exclude endocarditis and cardiac enlargement, as well as endocardial murmurs that occur in dogs with changes in hemodynamics in the body (unlike murmurs due to heart defects, they are unstable, blowing in nature, often systolic).

The insertion of a pacemaker is an effective measure for heart rhythm disturbances in dogs that quickly tire from exercise. A pacemaker lasts a dog's entire life. It is inserted into the jugular vein and communicates with the heart. The wires are connected to the pulse generator. The latter is sewn into the neck under the skin, so after the operation you have to use a harness instead of a collar.

Endocarditis is accompanied by an increase in body temperature. Endocardial murmurs are less constant and do not always occur (functional murmurs).

The prognosis depends on the degree of compensation and severity. With good compensation, dogs with heart disease can be active for a long time, but they need to be under constant veterinary supervision.

With congenital heart defects, the prognosis in most cases is unfavorable.

Treatment of heart defects in carnivores is pointless; You can only mitigate certain symptoms of a cardiac disorder.

During the compensation period, treatment should be aimed at eliminating conditions that adversely affect the heart.

Treatment of dogs: Directory of veterinarian Arkadyeva-Berlin Nika Germanovna

The structure of the dog’s respiratory system and its features

The apex of the nose does not contain glands. It is based on the nasal cartilage and the cartilaginous septum. The nasal planum is usually pigmented. Along the midline there is a continuation of the groove of the upper lip - the filter. The nostrils narrow into a slit bordered by the upper and lower wings, which are inactive. Short-headed dogs often have difficulty breathing noisily, accompanied by wheezing - due to too narrow nostrils.

The structure of the dog's dorsal shell is common for the anatomy of carnivores. The ventral shell is large and strongly folded. The middle passage is divided into two arms by the far-penetrating endoturbinal of the ethmoid labyrinth (middle concha). The labyrinth of the ethmoid bone itself is also significantly complicated. Due to these features, the surface of the olfactory epithelium in dogs ranges from 67 cm2 (spaniel) to 170 cm2 (shepherd), and the number of olfactory neurons can exceed 200 million.

Respiratory system of a bulldog (side view)

The larynx is located at the level of the I–II cervical vertebrae and has an almost cubic shape. The main cartilages of this organ are the elastic epiglottis, two arytenoids, the short thyroid cartilage and the large annular cartilage. The structure of the dog's larynx can also be supplemented by a small flat interarytenoid cartilage and sphenoid cartilages. The latter lie on both sides of the epiglottis and are attached to the arytenoid cartilages by connective tissue.

The trachea has a cylindrical shape, is somewhat flattened dorsoventrally, and contains 42-46 cartilaginous rings. The bifurcation is located at the level of the 4th rib.

The lungs are divided into lobes by deep incisions from the base of the lobar bronchus. The apical (cranial) lobe of the right lung is bifurcated. The cardiac (middle) lobes of a healthy dog ​​do not extend laterally beyond the diaphragmatic (caudal) lobe. The caudal vena cava is surrounded superiorly by an accessory lobe. The right and left pleural sacs communicate in the posterior part of the mediastinum.

Respiratory system of a bulldog (frontal view)

From the book Physiology of Reproduction and Reproductive Pathology of Dogs author Dulger Georgy Petrovich

1.3. DEVELOPMENT OF GENITAL ORGANS AND FEATURES OF OVO- AND SPERMATOGENESIS During the process of embryonic development, male and female genital organs are simultaneously formed in an individual. The indifferent reproductive system consists of primary gonads, mesonephric (Wolfian) and

From the book Treatment of Dogs: A Veterinarian's Handbook author Arkadyeva-Berlin Nika Germanovna

Examination of the external organs of a dog With this type of examination, it is necessary to pay close attention to the condition of the mucous membranes of the eyes, skin and subcutaneous tissue, as well as lymphatic

From the book Dentistry of Dogs author Frolov V V

Study of the respiratory system The main points on which this type of examination is based are observation of respiratory movements, examination of the upper respiratory tract, bronchi, lungs and chest. OBSERVATION OF RESPIRATORY MOVEMENTS Breathing can

From the book Service Dog [Guide to the training of service dog breeding specialists] author Krushinsky Leonid Viktorovich

4 Diseases of the respiratory organs and cardiovascular system The dog’s respiratory system consists of air-carrying organs and a pair of gas exchange organs – the lungs. In the first - the tube-shaped nasal cavity, larynx, trachea - the air is analyzed, warmed and purified.

From the book Dog Diseases (non-contagious) author Panysheva Lidiya Vasilievna

Diseases identified during examination of the respiratory system External respiration provides air warming, its transportation and purification from large-dispersed impurities (dust, microorganisms). This type of breathing is carried out through the nose, larynx, trachea, bronchi and

From the book Age Anatomy and Physiology author Antonova Olga Alexandrovna

The structure of the dog's cardiovascular system and its features The dog's heart lies almost horizontally from the 3rd to the 7th ribs, wide, short with a blunt apex. The right atrium contains the vena cava and the right azygos vein. Four pulmonary organs flow into the left atrium. On

From the book Biology [Complete reference book for preparing for the Unified State Exam] author Lerner Georgy Isaakovich

The structure of the dog's oral cavity The oral cavity (cavum oris) is located in the lower part of the animal's head under the nasal region. Some bones of the skull, intrinsic muscles and a number of special organs take part in the formation of the oral cavity, which include: lips,

From the author's book

4. Respiratory system Respiration is the process of the body absorbing oxygen and releasing carbon dioxide. This vital process involves the exchange of gases between the body and the surrounding atmospheric air. When breathing, the body receives from the air

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Respiratory diseases V. A. Lipin

From the author's book

Examination of the respiratory system To determine respiratory disease when examining a dog, the following methods are used: inspection, palpation, percussion and auscultation. Additional methods include X-ray examination. By inspection

Service dog [Guide to the training of service dog breeding specialists] Krushinsky Leonid Viktorovich

4. Respiratory system

4. Respiratory system

Respiration is the process by which the body absorbs oxygen and releases carbon dioxide. This vital process involves the exchange of gases between the body and the surrounding atmospheric air. When breathing, the body receives the oxygen it needs from the air and removes the carbon dioxide accumulated in the body. The exchange of gases in the body must occur continuously. Stopping breathing for even a few minutes results in the death of the animal. Breathing is externally manifested by a series of alternating expansions and contractions of the chest. The breathing process is composed of: air exchange between the lungs and atmospheric air, gas exchange between the lungs and blood - external, or pulmonary, respiration, and gas exchange between blood and tissues - internal, or tissue, respiration. Breathing is carried out by an organ system, or respiratory apparatus. It consists of the airways - the nasal cavity, larynx, trachea and lungs. The chest also participates in the act of breathing.

Nasal cavity. The nasal cavity is the first section of the airways. The bony basis of the nasal cavity is the facial bones, the ethmoid bone and the anterior edge of the sphenoid and frontal bones. Inside, the nasal cavity is divided into two halves by the nasal septum. Its anterior part is cartilaginous, and its posterior part is bone. The nasal cavity begins with two, somewhat split below, openings called nostrils. The walls of the nostrils are formed by lateral cartilages that extend from the front of the nasal septum. These cartilages prevent the walls of the nostrils from collapsing when inhaling. Between the nostrils there is an area of ​​skin with a rough, slightly bumpy surface (usually black), devoid of hair, called the nasal planum. The movable part of a dog's nose is called the lobe. In a healthy dog, the nasal mucosa is always somewhat moist and cool.

In each half of the nasal cavity there are thin, spirally curved bone plates - the nasal turbinates. They divide the nasal cavity into three passages - lower, middle and upper. The lower nasal passage is narrow at first, but becomes wider posteriorly and merges with the middle passage. The upper passage is narrow and shallow. The lower and middle nasal passages serve for the passage of air during quiet breathing. When you inhale deeply, a stream of air reaches the upper nasal passage, where the organ of smell is located (Fig. 48).

Rice. 48. Dog's nasal cavity

1 - inferior nasal concha; 2 - superior nasal concha

The initial part of the nasal cavity is covered with flat, stratified epithelium, which in the deeper parts turns into columnar, ciliated epithelium. The latter is characterized by the fact that at the free end of the cell there are bundles of thin mobile filaments called cilia or ciliated hairs, which is where the name epithelium comes from.

Passing through the nasal cavity, the air warms up (up to 30–32°) and is cleared of foreign mineral and organic particles suspended in it. This is facilitated by the large surface of the folded mucous membrane, covered with ciliated epithelium, the purpose of which is to trap small particles of air dust with the movement of its cilia, which are then released from the nose with mucus. Irritation of the eyelashes causes sneezing.

In the olfactory region of the mucous membrane there are cells of special sensitivity, the so-called olfactory cells. Irritation by particles of odorous substances causes the sensation of odor. This part of the nasal cavity serves as the organ of smell.

Larynx. The inhaled air, heading from the nasal cavity to the trachea, passes through the larynx. The larynx lies under the entrance to the esophagus, communicating with the nasal cavity through the nasopharynx. The larynx consists of five cartilages connected to each other by muscles and ligaments. One of these cartilages, enclosing the entrance to the trachea in a ring, is called annular or cricoid, the other is called thyroid, and the two located above are called arytenoid. The anterior cartilage that projects into the pharynx is called the epiglottis.

The laryngeal cavity is lined with mucous membrane covered with ciliated epithelium. Irritation of the mucous membrane of the larynx causes a cough. On the inside of the larynx, the mucous membrane forms folds based on the vocal cords and muscles. The vocal cords, with their free ends directed towards each other, limit the glottis. When the muscles contract, the vocal cords tighten and the glottis narrows. The strong exhalation movement of air causes the tense vocal cords to vibrate, resulting in the creation of sound (voice).

Trachea, or windpipe. The trachea is a tube consisting of annular cartilaginous plates (a type of corrugated gas mask tube). In dogs, the trachea has an almost cylindrical shape. The ends of the cartilaginous plates do not reach each other. They are connected by a flat transverse ligament, which protects them from damage when pressed, for example, by a collar. From the side of this ligament, the trachea is adjacent to the esophagus located above it. The mucous membrane lining the trachea is covered with ciliated epithelium, between the cells of which individual mucous glands are scattered. The cilia of the ciliated epithelium oscillate towards the larynx, due to which the secreted mucus, and with it small particles of dust, are easily removed from the trachea (Fig. 49).

Rice. 49. Scheme of branching of the bronchi

When there is a significant accumulation, they are expelled by coughing impulses.

Lungs. A dog has two lungs - right and left. The lungs lie in the chest cavity, occupying it almost completely and are supported in their position by the bronchi, blood vessels and fold of the pleura. Each lung is divided into three lobes - apical, cardiac and diaphragmatic. The dog has an additional lobe in the right lung (Fig. 50 and 51).

Rice. 50. Light dogs

The structure of the lungs is as follows. The trachea, entering the chest cavity, is divided into two large bronchi, which enter the lungs. In the lungs, the bronchi branch into smaller branches and approach the so-called respiratory lobules in the form of terminal bronchi. Entering the lobules of the lung, each bronchus is divided into branches, the walls of which protrude into a large number of small sacs called pulmonary alveoli. It is in these alveoli that gas exchange occurs between air and blood.

Rice. 51. Cast of two lobes of bronchi

The pulmonary artery approaches the lungs from the heart. Entering the lungs, it branches parallel to the bronchi and gradually decreases in size. In the lobules of the lung, the pulmonary artery forms a dense network of tiny vessels - capillaries surrounding the surface of the alveoli. Rice. 51. Cast of two lobes of bronchi. Having passed the alveoli, the capillaries, merging into larger vessels, form the pulmonary veins, running from the lungs to the heart.

Thoracic cavity. The chest cavity has the shape of a cone. Its lateral walls are the skeleton of the chest with the intercostal muscles, the diaphragm is located at the back, and the cervical muscles, blood vessels and nerves are at the front.

The chest cavity is lined with a serous membrane called the parietal pleura. The lungs are also covered by a serous membrane called the pulmonary pleura. Between the parietal and pulmonary pleura there remains a narrow gap filled with a small amount of serous fluid. In this narrow gap there is negative pressure, as a result of which the lungs are always in a somewhat stretched state and are always pressed close to the chest wall and follow all its movements.

In addition to the lungs, the thoracic cavity contains the heart and the esophagus, blood vessels and nerves.

Breathing mechanism. To inhale, the chest cavity must expand. The intercostal muscles contract and raise the ribs. In this case, the middle of the ribs rises upward and moves away somewhat from the midline, and the sternum, motionlessly connected to the ends of the ribs, follows the movement of the ribs. This increases the volume of the chest cavity. The expansion of the thoracic cavity is also facilitated by the movement of the diaphragm. In a calm state, the diaphragm forms a dome, the convex part of which is directed towards the chest cavity. When inhaling, this dome becomes flatter, the edges of the diaphragm adjacent to the chest wall move away from it, and the chest cavity increases. With each expansion of the chest, the lungs passively follow its walls and expand with the pressure of the air in the alveoli. The pressure of this air, due to the increase in the volume of the alveoli, becomes less than atmospheric pressure, as a result of which outside air rushes into the alveoli and inhalation occurs.

After inhalation comes exhalation. During exhalation, the muscles of the chest and diaphragm relax. The costal ligaments and cartilages, due to their elasticity, tend to return to their previous position. The abdominal organs (liver, stomach), pushed aside by the diaphragm during inhalation, return to their normal position. All this causes a decrease in the chest cavity, the walls of which begin to put pressure on the lungs, and they collapse. In addition, the lungs collapse due to their elasticity, and at the same time the air pressure in them becomes greater than atmospheric pressure, which creates conditions that promote the pushing of air from the lungs outward - exhalation occurs. With increased exhalation, the abdominal muscles are also actively involved. They push the abdominal organs toward the chest, which increases pressure on the diaphragm.

When exhaling, the lungs are not completely freed from the air they contain, which is called residual air.

There are three types of breathing: abdominal, thoracic and costo-abdominal. In a calm state, a dog's breathing type is abdominal. With deep breathing it becomes costo-abdominal. Chest breathing occurs only with shortness of breath.

The respiratory rate, i.e. the number of inhalations and exhalations per minute, in a dog in a calm state ranges from 14 to 24. Depending on various conditions (pregnancy, age, internal and external temperature), the respiratory frequency may vary. Young dogs breathe more quickly. The dog's breathing rate increases greatly during heat and during muscular work.

Respiratory movements are regulated by the respiratory center located in the medulla oblongata. Excitation of the respiratory center occurs predominantly automatically. An excess of carbon dioxide appears in the blood washing it, which excites the cells of the respiratory center. This creates a unique system of self-regulation of breathing. On the one hand, the accumulation of carbon dioxide causes increased ventilation of the lungs and promotes the removal of carbon dioxide from the blood. On the other hand, when increased ventilation of the lungs leads to saturation of the blood with oxygen and a decrease in the carbon dioxide content in it, the excitability of the respiratory center decreases and breathing is delayed for some time. The sensitivity of the respiratory center is very great. Breathing changes sharply during muscular work, when the products of muscle metabolism (lactic acid) do not have time to oxidize and enter the blood in significant quantities, stimulating the respiratory center. Excitation of the respiratory center can also occur by reflex, that is, as a result of excitation of peripheral nerves going to the medulla oblongata. For example, painful sensations can cause a short cessation of breathing, followed by prolonged wheezing, sometimes accompanied by a groan or bark. A short cessation of breathing also occurs when the end is exposed to cold, for example, when immersed in cold water.

Exchange of gases in the lungs and tissues. The exchange of gases in the lungs and tissues occurs due to diffusion. The essence of this physical phenomenon is as follows: the air entering the alveoli of the lungs contains more oxygen and less carbon dioxide than the blood flowing to the lungs. Due to the difference in gas pressure, oxygen will pass through the walls of the alveoli and capillaries into the blood, and carbon dioxide will pass in the opposite direction. Therefore, the composition of exhaled and inhaled air will be different. Inhaled air contains 20.9% oxygen and 0.03% carbon dioxide, and exhaled air contains 16.4% oxygen and 3.8% carbon dioxide.

Oxygen entering the blood from the alveoli of the lungs is distributed throughout the body. The cells of the body are in dire need of oxygen and suffer from excess carbon dioxide. Oxygen in cells is consumed for oxidative processes, so there is less oxygen in cells than in blood. Carbon dioxide, on the contrary, is constantly formed and there is more of it in the cells than in the blood. Due to this difference between blood and tissues, gas exchange or so-called tissue respiration occurs.

The connection between the respiratory organs and the functions of other organs. The respiratory organs are closely related to the circulatory system. The heart lies next to the lungs and is partially covered by them. Constant ventilation of the lungs during breathing cools the heart muscle and protects it from overheating.

Breathing movements of the chest promote blood circulation.

The respiratory organs are closely related to digestion. When breathing, the diaphragm puts pressure on the abdominal organs and especially on the liver, which promotes better secretion of bile. The diaphragm helps the act of defecation. Breathing is also closely related to muscles. Even slight muscle tension causes increased breathing.

The respiratory organs serve as an important factor in thermoregulation.

From the book Treatment of Dogs: A Veterinarian's Handbook author Arkadyeva-Berlin Nika Germanovna

Study of the respiratory system The main points on which this type of examination is based are observation of respiratory movements, examination of the upper respiratory tract, bronchi, lungs and chest. OBSERVATION OF RESPIRATORY MOVEMENTS Breathing can

From the book Service Dog [Guide to the training of service dog breeding specialists] author Krushinsky Leonid Viktorovich

4 Diseases of the respiratory organs and cardiovascular system The dog’s respiratory system consists of air-carrying organs and a pair of gas exchange organs – the lungs. In the first - the tube-shaped nasal cavity, larynx, trachea - the air is analyzed, warmed and purified.

From the book Dog Diseases (non-contagious) author Panysheva Lidiya Vasilievna

The structure of the dog's respiratory system and its features The apex of the nose does not contain glands. It is based on the nasal cartilage and the cartilaginous septum. The nasal planum is usually pigmented. Along the midline there is a continuation of the groove of the upper lip - the filter. Nostrils

From the book Homeopathic treatment of cats and dogs by Hamilton Don

Diseases identified during examination of the respiratory system External respiration provides air warming, its transportation and purification from large-dispersed impurities (dust, microorganisms). This type of breathing is carried out through the nose, larynx, trachea, bronchi and

From the book Age Anatomy and Physiology author Antonova Olga Alexandrovna

2. System of organs of movement The system of organs of movement serves to move individual parts of the body in relation to each other and the whole organism in space. The system of organs of movement is formed by the bone and muscular apparatus of movement. Bone apparatus of movement. Organs

From the book Biology [Complete reference book for preparing for the Unified State Exam] author Lerner Georgy Isaakovich

3. Digestive system The dog's body is built from complex organic substances - proteins, carbohydrates, fats. The most important of these is protein. In addition to these organic substances, the body also contains inorganic substances - salts and a large amount of water (from 65 to

From the author's book

5. Blood and lymph circulatory system Cells of the body require constant delivery of nutrients and removal of unnecessary and harmful substances - the products of their vital activity. These functions in the body are performed by the blood and lymph circulatory system. System

From the author's book

6. Urinary organ system In the process of constantly occurring metabolism in the body, waste products of cell nutrition and mainly protein breakdown products that are harmful to the body are formed. In addition, substances that are not harmful accumulate in the body, but

From the author's book

7. System of reproductive organs Reproduction is one of the most important functions of the body and ensures procreation. To perform functions related to reproduction, dogs use the reproductive apparatus. The reproductive apparatus of a male dog. The male reproductive system consists of

From the author's book

8. System of internal secretion organs Internal secretion organs are glands that produce and release special substances - hormones - directly into the blood. A characteristic feature of hormones is their ability to exert

From the author's book

Respiratory diseases V. A. Lipin

From the author's book

Examination of the respiratory system To determine respiratory disease when examining a dog, the following methods are used: inspection, palpation, percussion and auscultation. Additional methods include X-ray examination. By inspection

From the author's book

Chapter IX The respiratory system, nose and sinuses The air we breathe Clean, fresh air nourishes the lungs and cleanses the soul - just as good nutrition provides vital energy to the body (it is no coincidence that the words “soul” and “breath” come from the same root in all languages) .

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Topic 8. AGE FEATURES OF THE RESPIRATORY ORGANS 8.1. Structure of the respiratory organs and vocal apparatus. Nasal cavity. When you breathe with your mouth closed, air enters the nasal cavity, and when you breathe open, it enters the oral cavity. Bones and cartilages are involved in the formation of the nasal cavity, of which

From the author's book

8.1. Structure of the respiratory organs and vocal apparatus. Nasal cavity. When you breathe with your mouth closed, air enters the nasal cavity, and when you breathe open, it enters the oral cavity. The formation of the nasal cavity involves bones and cartilage, which also make up the nasal skeleton. Most of