Study of the heart and its topography. General clinical examination of dogs and cats

U cattle the base of the heart is at the level of half the height of the chest. Most (5/7) of the organ is placed to the left of the middle of the chest cavity; its rear edge descends from top to bottom and to the left. The inclination of the heart from front to back is approximately 70°. The upper percussion border reaches a horizontal line drawn from the scapular shoulder joint, and the back reaches the fifth rib.
In pigs the base of the heart is located halfway up the height of the chest. The upper percussion border is located at the level of the scapulohumeral joint and occupies a middle position, only its apex is shifted to the left and separated from chest wall, and the posterior edge descends down behind the sixth rib.
At the horse 3/5 of the heart is located in the left half of the chest. The heart occupies the space from the third to the sixth rib; its base is slightly below the middle of the chest (two fingers below the line of the scapulohumeral joint), and its apex is in the fifth intercostal space 2 cm above the surface of the sternum. Posterior border the heart on the left side reaches the sixth, and on the right - to the fifth rib. On the left side, part of the surface of the heart, an area of ​​about 10 cm2 in the area of ​​the fourth and fifth ribs, is not covered by the lungs.
In dogs the heart is located from the 3rd to the 6-7th ribs; 4/7 of the heart is located on the left, and 3/7 on the right side of the chest cavity. The base is located at half the height of the chest, and the apex is 1 cm above the surface of the chest. The upper border of the heart is 1-2 fingers below the horizontal line of the scapulohumeral joint, and the posterior border is along the seventh rib.
Examination of the cardiac region.
To examine the area where the heart is located, you need to move or extend the left thoracic limb of the animal forward. In this case, a cardiac impulse is indicated - in the form of a concussion of the chest wall or hair vibrations.
In cattle, the cardiac impulse is noticeable at the level of the elbow on the left side in the region of the 3rd-5th intercostal space. Most intense in the fourth intercostal space.
In small animals, the apex beat is visible.
In animals with poor nutritional status, heartbeats are clearly visible, but with increased nutritional status they become less noticeable.
Palpation of the cardiac region.
Palpation determines the strength of the cardiac impulse (strengthening, weakening), as well as the vibration of the chest in the area of ​​the heart and possible displacements of the impulse. The palpation method is also used to determine the pain reaction in the heart area (acute fibrinous pericarditis).
Palpation of the area of ​​the heart in large animals is carried out on the left side with the left hand, the right hand is placed on the back or withers of the animal. In small animals, palpation can be performed on both sides simultaneously. To do this, stand in front of the animal and inspect and palpate the lower and lateral surface of the chest in the area of ​​the heart.
With tympany, expansion of the stomach and intestines with gases, the heart impulse is shifted forward; the impulse shifts back and upward with pericarditis, and with left-sided pleurisy it is better visible on the right side. Inspection and palpation of the cardiac region are performed simultaneously, as they complement each other.
Gain heart beats are observed during work, with nervous excitement, fever.
knocking a cardiac impulse occurs in acute forms of heart disease.
Weakening cardiac impulse occurs in inflammatory and degenerative diseases of the heart muscle, with accumulation large quantity exudate in pleural cavity, as well as in the heart shirt, with expansion of the lungs.
Vibration, trembling of the chest wall in the area of ​​the heart, which can be felt with some heart defects and inflammation of the pericardium.
Percussion of the cardiac region.
Percussion of the heart area aims to establish the boundaries of the location of the heart, the magnitude of absolute and relative dullness. From these data one can judge the size of the organ, its possible displacements and changes.
The part of the heart not covered by the lungs is directly adjacent to chest and produces a dull sound when percussed. This area is usually called absolute cardiac dullness. Most of the organ is covered with lungs and produces sound when percussed. relative cardiac dullness. The zone of relative dullness turns into a clear pulmonary sound.
It is better to perform percussion in the arena, at a distance of 1.5 m from the wall. Small animals are examined on a table. Percussion is usually performed on the left side. To do this, the left thoracic limb of the animal is placed forward.
In large animals, instrumental percussion is performed, and in small animals, digital percussion is more common. In all animals, tapping is carried out along two lines (Fig. 32): along the posterior line of the ancaneus and from the place of cardiac dullness (ulnar tubercle) towards the maklok. The zone of relative cardiac dullness is determined by the transition of a clear pulmonary sound to a dull one, and the border of absolute dullness is determined by the transition of a dull sound to a dull one. Percussion begins from top to bottom along the line of the ancaneus, and in healthy animals, clear pulmonary sounds first appear, then relatively dull and dull sounds. A relatively dull sound is determined by strong percussion, while the boundaries of absolute dullness are determined by light tapping. The transition of a clear pulmonary sound to dullness indicates the border of the heart region.

Heart and cardiovascular system of cats.

Based on materials from www.merckmanuals.com

Additional Information:
Heart disease in cats
Congenital and hereditary heart diseases
Cardiomyopathy
Acquired diseases
Heart failure
Blood clots and aneurysms
Heart murmurs

The cardiovascular system of cats includes the heart itself and blood vessels - veins and arteries.

The structure of a cat's heart.

Heart performs the functions of a pump - pumps blood. The right side of the heart pumps blood to the cat's lungs, where the blood is oxygenated. Left-hand side serves other organs, delivering blood and nutrients, as well as removing waste products (such as, for example, carbon dioxide). The cat's heart is a hollow muscular organ, which (like all mammals and birds) is divided into four chambers. Muscular middle layer The heart is called the myocardium. The upper chambers of the left and right sides of the heart are called the atria (left and right, respectively). Both lower chambers are called ventricles - also left and right.

Job of cardio-vascular system cats.

A set of valves allows blood to move through the cat's heart into in the right direction. Atrioventricular valves are located between the atria and ventricles of the heart. The semilunar valves are located at the exit of the aorta and pulmonary artery from the ventricles of the heart. Each ventricle of the heart has an inlet and outlet valve. In the left ventricle, the inlet valve is called the mitral valve and the outlet valve is called the aortic valve. In the right ventricle, the inlet valve is called the tricuspid valve, and the outlet valve is called the pulmonary valve.

Blood from the body enters right atrium through two large veins called vena cava.

When the right valve is open, blood flows into the right ventricle through the tricuspid valve. When the right ventricle is close to filling, the right atrium contracts, adding more blood to the right ventricle. The right ventricle itself then contracts, pushing blood through the pulmonary valve into the pulmonary artery, which goes to the cat's lungs. In the lungs, the blood absorbs oxygen and releases carbon dioxide. After this, blood through the pulmonary veins into left atrium.

At the moment when the right valve is open, blood enters the left atrium through mitral valve left ventricle. After the left ventricle becomes almost full, the left atrium contracts and more blood enters the left ventricle. The left ventricle then contracts, pushing blood through the aortic valve into the aorta, the largest artery in the cat's body. This blood carries oxygen through the aorta throughout the body, with the exception of the lungs.

The work of a cat's heart.

Each contraction of the heart occurs in two stages - diastole And systole. The first stage is diastole, which can be tracked by the sound of the mitral and tricuspid valves closing. The second stage - systole, is determined by the sound of aortic closure and pulmonary valves. During diastole, the ventricles relax and fill with blood, and during systole, they contract and push out blood.

The frequency and strength of heart contractions, as well as the degree of filling of the narrowing or dilating of blood vessels, are controlled by certain hormones and the autonomic nervous system (part nervous system, which controls unconscious activity).

Heartbeat.

A cat's heart beats because it receives very weak electrical impulses from the sinus (or sinoatrial) node. This node for the heart is the natural pacemaker. Periodic electrical impulses or discharges from the sinus node cause contraction of the muscle fibers of the heart. While the cat is at rest, sinus node continues its work, delivering shocks - for a relaxed cat normal frequency is about 200 discharges per minute.

Heart rate has inverse relationship from blood pressure. When the pressure increases, the rhythm slows down, and when it decreases, the pulse frequency increases.

Sounds and heart murmurs of cats.

The heart makes sounds because the flow of circulating blood speeds up and slows down, causing vibrations in the heart. Heart sounds can be heard with a stethoscope. For cats, two heart sounds can be distinguished normally.

Heart murmurs are vibrations that can be heard in the heart or major blood vessels. Typically, vibrations are caused by turbulence in the bloodstream or structures of the heart, such as parts of the valves. Noises are typically described by their timing (that is, whether they are heard constantly or only intermittently), their intensity (that is, whether they can be heard easily or with difficulty), and by the location of their source. Not all murmurs are signs of heart problems; for example, murmurs can almost always be heard in the hearts of kittens up to six months of age.

Arrhythmia in cats.

Arrhythmia- This is a violation of the heart rate, regularity or correct form of the heartbeat. Arrhythmia does not always indicate problems with the cat's heart. Many types of arrhythmia have no functional significance and do not require special treatment. Some types of arrhythmia, however, can cause severe consequences, such as loss of consciousness, due to lack of blood flow to the brain or even lead to sudden death of the cat. Many diseases are associated with disturbances in the normal rhythm of the heart.

Pulse of cats.

Pulse is a rhythmic dilatation of the arteries that can be felt with the fingertips during a physical examination of the cat. In a cat, the pulse is usually checked in the hip area (at the femoral artery). U healthy cat You can feel the pulse in the neck in the jugular cavity. The pulse may be absent, strengthened or weakened - all of which may indicate a certain type of heart disease or defect.

Percussion of the heart region is one of the most difficult diagnostic tasks. They are carried out to determine the boundaries of the heart, from which one can get an idea of ​​its size, shape and position in the chest, as well as to establish the sensitivity of the heart and the nature of the percussion sound.

Percussion is carried out with the forelimb retracted as far forward as possible; in large animals, mediocre instrumental percussion is more often used, and in small animals, mediocre digital percussion is used.

The heart is only partially adjacent to the chest wall, since along the periphery it is covered by the pulmonary edges. By percussing the area of ​​the heart from top to bottom along the intercostal spaces, you can detect the transition of a clear pulmonary sound into a dull one, then into a dull one. The area of ​​the heart adjacent to the chest wall produces a dull sound (zone of absolute dullness of the heart), and that covered by the lungs produces a dull sound (zone of relative dullness of the heart).

The boundaries of relative cardiac dullness correspond to the projection of the surface of the heart onto the chest and are the true boundaries of the heart.

Absolute dullness is normally recorded in horses, foxes, and dogs; it is not found in most other animals, since the cardiac notch is easily covered by a thick layer of pectoral girdle muscles.

Cardiac percussion technique.

In large animals, percussion of the heart area is carried out using a percussion hammer and plessimeter (instrumental percussion) in the generally accepted way, but in small animals it is more convenient to percussion with the fingers (digital percussion). The percussion boundaries of the heart are determined on the left, and when diagnosing right ventricular hypertrophy, pericarditis and other indications, right-sided percussion is also performed. The boundaries of relative dullness are better recognized with stronger percussion, and absolute dullness, on the contrary, at the threshold of auditory perception (“threshold percussion”). Percussion is carried out with the animal standing; percussion the heart area in two directions:

1) along the posterior vertical line of the anconsuses;

2) from the ulnar tubercle to the maklok.

The researcher should be on the side on which percussion is performed. Auditory perception occurs at the level of percussion sounds. In large animals, the corresponding thoracic limb is set aside, bent at the carpal joint and pulled forward. In cattle and monoungulates, only the dorsal and caudal boundaries of cardiac dullness can be accurately determined, and in carnivores, the part of the cardiac region covered by the sternum is also percussed (when the animal is sitting).

In cattle, the zone of heart dullness is weakly expressed and is located in the subscapular region at the apex of the angle formed by a vertical line going to the head of the ulnar tubercle and a line inclined to it, going at an angle of 45°. Percussion is difficult even with strong abduction of the limb. Relative dullness of the heart on the left is percussed in the 3rd-4th intercostal spaces. Its upper border reaches the line of the shoulder joint, and its posterior border reaches the 5th rib. The lower percussion border of the heart coincides with the dullness formed by the sternum. In the 3rd intercostal space, this dullness is recognized only when the left thoracic limb is pulled forward, and in the 4th intercostal space, on the contrary, it is more accessible to research. On the right, the percussion sound of dullness is not detected.

In sheep and goats, three boundaries of cardiac dullness are established: anterior, in the 3rd intercostal space; posterior - up to the 5th rib; the upper one is 1-2 cm below the line of the scapulohumeral joint. Relative dullness of the heart is detected only in the 3rd-4th intercostal spaces from the midline of the sternum to the middle of the lower third of the chest. On the right side, percussion normally does not produce results.

In horses and other single-hoofed animals, 3/5 of the heart is located in the left half of the thoracic cavity, and its apex is in the 5th intercostal space 2 cm above the upper border of the sternum. On the left, in the area of ​​the 4th-5th ribs, it is in the form of a triangle adjacent to the chest wall, creating an area of ​​dullness. The upper limit of the relative dullness of the heart normally runs in the 3rd intercostal space on the left, 2-3 cm below the line of the scapulohumeral joint, and the posterior limit reaches the 6th rib. The area of ​​absolute dullness of the heart has the shape of a triangle, its anterior border goes along the line of the anconeus, the posterior border is directed from top to bottom and goes in an arcuate manner from the 3rd intercostal space to the lower edge of the 6th rib, and the lower border passes without a sharp border into dullness sternum and its muscles. The height of the triangle in the 3rd intercostal space is 10-13 cm, depending on the size of the animal. The area of ​​absolute dullness on the right is much smaller in size and occupies the lowest part of the 3rd and 4th intercostal spaces. The area of ​​relative cardiac dullness on both the left and right is in the form of a strip 3-5 cm wide surrounding the absolute dullness of the heart.

In pigs, the upper limit of the relative dullness of the heart reaches the level of the shoulder joint, and the posterior limit reaches the 5th rib. In animals of good nutrition, percussion does not always give positive results.

In carnivores, percussion of the cardiac region is carried out along three boundaries:

1) anterior - along the anterior edge of the 3rd rib;

2) upper - 2-3 cm below the scapulohumeral joint;

3) posterior - up to the 7th rib.

Absolute dullness of the heart is detected in the 4th-6th intercostal spaces. Its anterior border starts from the middle of the sternum parallel to the caudal edge of the 4th rib, goes vertically to the costal symphyses, and the dorsal border runs horizontally in the 4th-5th intercostal spaces and reaches the 6th intercostal space, forming a curve curved back. Caudally, without a sharp border, it passes into the zone of hepatic dullness, and from the midline of the sternum into the right-sided cardiac dullness in the 4th or 5th intercostal space at 1-2 cm dorsal to the upper edge of the sternum. In this case, one merging zone of dullness is formed on the ventral part of the chest, which is clearly visible in dogs when they are sitting.

The boundaries of cardiac dullness can also be established by percussion along arcuate curves, approaching the boundaries from the periphery, as well as along the intercostal spaces.

Changing the boundaries of cardiac dullness depends on the size of the heart and the nature of pathological changes in the pericardial sac and lungs. Thus, with an increase in the volume of the heart, for example, with its expansion and hypertrophy, the boundaries of relative and absolute dullness shift, and with an increase in individual parts of the heart, the configuration of the cardiac region changes dullness. So, if only the left ventricle is enlarged, its posterior border in the lower part of the area of ​​cardiac dullness shifts, then only the atria - its posterior border in the upper part of the area of ​​cardiac dullness shifts, the right ventricle - the area of ​​dullness on the right side increases, etc.

The accumulation of fluid in the cavity of the pericardial sac leads to displacement of the edges of the lungs from the surface of the heart, as a result of which an area of ​​absolute dullness appears or increases, its boundaries shift upward and backward.

A displacement of the boundaries of the area of ​​cardiac dullness occurs in the same cases as a displacement of the cardiac impulse.

A tympanic sound in the heart region occurs with traumatic pericarditis as a result of the formation of gases in the pericardial sac, with fibrinous pneumonia in the stage of hyperemia, pneumothorax.

Pain on percussion in the heart area is observed when inflammatory processes in the tissues of the chest wall, pleurisy, pericarditis, etc.

Auscultation of the heart ranks first among research methods, as it makes it possible to most fully study sound phenomena associated with the work of a healthy and diseased heart. Both indirect and direct auscultation can be used to listen to the heart. Direct auscultation is carried out with the right ear, which is firmly applied to the chest wall in the area behind the elbow. In restless horses, auscultation is best done with the left ear, which is applied to the rear edge muscle group anconeus. The auscultation zone can be significantly expanded if the animal's left front leg is moved slightly forward. It is necessary to take into account that prolonged standing tires the animal and it begins to worry. This creates extraneous noises that make research very difficult. Examination with the left ear in the area of ​​the anconeus muscle group has the advantage that the animals stand quietly, and although the sounds are somewhat weaker than when the leg is abducted, the examination can be done slowly, without forced breaks.

Mediocre auscultation using a phonendoscope or soft stethoscopes is carried out in all cases to determine the points of best audibility of heart sounds and analyze them qualitative changes, to determine noise and when functional diagnostics. The advantages of intermediate auscultation are that it allows animals to be heard in any position.

Heart sounds. When listening normal heart You can hear two rhythmically repeating sounds called heart sounds. They are short-lived, have some musicality and resemble the flapping of stretched fabric. The tones are separated from each other by pauses of varying lengths. The tone heard before a short pause coincides in time with the heart beat and pulse carotid artery, i.e. with ventricular systole, which is why it is called systolic, or first, sound. The tone that occurs after a short pause refers to the period of ventricular relaxation and is called the diastolic, or second sound.

Heart sounds occur due to tissue tension during its operation. Sounds are produced by tissues capable of vibratory vibrations. Such tissues include the valvular semilunar valves and the fibrous ostia of the aorta and pulmonary artery. Contraction of muscle tissue produces sounds that are weaker, but longer lasting than valves and fibrous openings.

The sounds arising in different parts of the heart merge into one common sound. The sound of the flap valves is distinguished by the greatest power, which dominates the formation of the tone and gives it a peculiar shade.

The first, or systolic, tone is particularly complex in its origin. It consists of: a) the sounds of the bicuspid and tricuspid, which contract simultaneously during ventricular systole; b) sounds of stretched connective tissue ostia of the aorta and pulmonary artery and c) muscle tones of contracting right and left ventricles of the heart. All these sound phenomena merge into the first tone. The diastolic, or second, sound is formed from two sounds merging into one - the slamming of the valves of the aorta and pulmonary artery.

In pathological conditions, a change in tone depends on qualitative changes in individual components included in one or another tone, and therefore the ability to identify and isolate individual components allows one to establish the cause and localization of the process.

In humans, there is also a third heart sound, which occurs at the beginning of diastole, i.e., in the protodiastolic period. The occurrence of the third sound is based on the flow of blood into the empty ventricle from the atria with stretching of their relaxed wall (Gubergritz).

In terms of the nature of the sound, both tones differ sharply from one another. The first tone is louder, much longer and stretched out at the end; the second tone is shorter, higher and has a clapping character. The end of the second tone is abruptly cut off. Phonetically, the combination of the first and second tone can be represented in the form of repeated syllables: buu-tup, buu-tup, buu-tup. The stress during auscultation in the fourth and fifth intercostal spaces falls on the first tone (trochee rhythm).

In large animals, the difference in sounds is so well expressed that differentiation of tones normally, with relatively rare cardiac activity, does not present any difficulty. In small animals, with more accelerated heart function, simultaneous auscultation and palpation can be used. The systolic tone coincides with the cardiac impulse. The simultaneous perception of tactile and auditory impressions can also be used in large animals when cardiac activity increases.

Differentiation of tones when normal operation The heart also helps, in addition, the difference in pauses between the first and second tone and between the second and first tone. There is a short pause between the first and second tone, its duration is large dogs equal to 0.2 seconds. The pause between the second and the first is 2 times longer and reaches 0.43 seconds in dogs. A kind of rhythm is created. The first tone follows a long pause, and the second tone follows a short one. During normal heart activity, all of the listed features in the work of the heart make it possible to easily distinguish heart sounds from one another, to distinguish a normal heart melody from a pathological one.

During febrile processes, the heart's work accelerates significantly. The shortening of the refractory period affects the duration of the intervals between tones, due to which the pauses become equal to one another. The nature of the tones changes, the differences between them are smoothed out, and they become similar to one another. To differentiate in these cases it is necessary to use tactile and auditory perception. The first tone coincides with the heartbeat.

Points of best audibility of cardiac tones (Punctum optimum). The shortest distance from the heart opening - the source of sound - is called the projection of the orifices of the heart, or the points of best audibility of heart sounds. The shortest distance is determined by the perpendicular restored from this hole to the surface of the chest. The intersection of the perpendicular with the surface of the chest wall will be the projection of this opening of the heart. The individual components that make up the first and second tones are formed in the lumen of the heart

Holes spaced at some distance from one another. Naturally, the transmission of sounds to the chest at different points is not the same. This depends both on the distance between the points of their formation and on the point where auscultation is performed. The point where the intensity of the tone will be stronger, and the other valve similar to it will be weaker, is called the Punctum optimum of heart tones.

Determining the points of best audibility of a tone has a huge practical significance. In pathological conditions, it is possible to determine the localization of the process.

The projection of the bicuspid valve, or P. optimum bicuspid, is located in the horse in the fifth intercostal space on the left, in the middle of the lower third of the chest. During auscultation, both tones are heard at this point, but one of them, the systolic one, in which the bicuspid sounds with particular force, is dominant.

The projection of the tricuspid valve, or P. optimum tricuspid, is located on the right side, under the fourth rib, at the level of the middle of the lower third of the chest. Of the two tones that are heard here, the systolic tone of the tricuspid is dominant. It should be noted that on the right side the heart tone is heard somewhat weaker than on the left side.

Projection of the aortic valve, or P. optimum aortic valve, is located in the fourth intercostal space on the left, slightly below the line drawn through the scapulohumeral joint. Due to its deep location, this tone is low-intensity and easily mixes with the tone of the pulmonary artery. On the right, in the same intercostal space, this tone is heard, although weaker, but almost pure. Projection of the opening of the pulmonary artery, or. P. optimum pulmonary artery, located in the third intercostal space on the left, in the middle of the lower third of the chest. Both tones are heard clearly, but the pulmonary artery tone is dominant.

In ruminants, the difference is that the projection of the bicuspid valve is located in the fourth intercostal space and in the same intercostal space, but slightly higher, is the projection of the aortic opening. The projection of the pulmonary artery is located in the third intercostal space on the left, almost in line with the bicuspid valve, and the projection of the tricuspid valve protrudes most clearly on the right, in the third intercostal space.

In a pig, the projection of the bivalve is in the fourth intercostal space on the left, the projection of the aortic opening is in the third intercostal space and the pulmonary valve is in the second intercostal space. The projection of the tricuspid valve is located on the right, in the third intercostal space.

In a dog, the projection of the bicuspid valve is located on the left in the fifth intercostal space above the line dividing the lower third of the chest in half, the projection of the aortic opening is in the fourth intercostal space on the left, directly below the line of the humeral tubercle. The projection of the pulmonary artery is located in the third intercostal space on the left along the edge of the sternum, and the tricuspid is located on the right in the fourth intercostal space at the height of the attachment of the ribs.

Increased heart sounds. Changes in the strength of heart sounds can be observed simultaneously and separately. An increase in both tones is observed in the following cases: a) increased heart contractions during physical stress and fevers; b) when poor nutrition and in animals with a narrow chest; c) when there is an anemic condition. In this case, heart sounds acquire a flapping character, apparently due to big difference tension in the tissues of valves and orifices during systole and diastole; d) when there is an improvement in sound transmission conditions.

Strengthening individual tones is called accent, or accentuation of heart tones. The accent of a tone is spoken of in cases where it stands out sharply from the general sound (accentuates). IN clinical practice What matters is the emphasis on the tone of the pulmonary artery, the emphasis on the second tone of the aorta and the emphasis on systolic sounds.

An emphasis on the second aortic sound is noted with increased blood pressure in arterial system. In healthy horses, emphasis on the aorta is detected when muscle tension and excitement of the animal. In pathological conditions, emphasis on the aortic valve is observed as a persistent phenomenon. Such processes include arteriosclerosis of the initial part of the aorta, increased blood pressure in big circle at chronic nephritis etc. An emphasis on the second sound of the pulmonary artery is observed in cases of increased blood pressure in the pulmonary circulation, when there is difficulty in blood circulation in the pulmonary circulation with sufficient strength of the right ventricle. Among the diseases in which there is an emphasis on the second sound of the pulmonary artery, alveolar pulmonary emphysema should be mentioned, interstitial pneumonia, bicuspid insufficiency and mitral stenosis. It should be taken into account that in young horses the tone of the pulmonary artery is much stronger than the tone of the aorta. With age, the intensity of the tone of the aorta gradually increases, and the pulmonary artery weakens.

Weakening of heart sounds. Heart sounds may appear weakened if sound conduction to the periphery is impaired. This can be due to obesity, subcutaneous emphysema, exudative pericarditis and with emphysema, when the heart moves away from the chest. This Need to Keep in mind not to recognize weakening of cardiac activity where it does not exist.

Weakening of heart sounds associated with impaired contractility of the heart muscle is observed with myocarditis, myodegeneration of the heart and with its expansion. It is also observed when the valves become thickened and deformed, preventing their contraction due to loss of elasticity. Further change results in noise. Weakening of sounds may occur with aortic valve insufficiency. The weakening is based on the inability of the bicuspid to move from a tense state during closure to an even greater tension during ventricular systole. The highest degree of disorder is the complete disappearance of heart sounds. In cattle, this symptom is characteristic of exudative traumatic pericarditis.

Split heart sounds. The splitting of heart sounds is based on either non-simultaneous contraction of both ventricles, which causes the splitting of the first tone, or their non-simultaneous relaxation, causing the splitting of the second tone. Non-simultaneous functioning of the ventricles is observed in diseases that unevenly affect both halves of the heart. Conditions for the occurrence of unequal work may be weakening of the heart and hypertrophy of one ventricle. The weakened ventricle lags behind the healthy one with its contractions, and its first sound is heard separately. Bifurcation can also be due to damage to one of the legs of the His bundle.

During ventricular diastole, the one that works against the lower blood pressure relaxes rather. For splitting the first tone especially favorable conditions are such when the systole of the left ventricle is shorter than the systole of the right, and the aorta closes before the pulmonary artery. An increase in blood pressure in the pulmonary circulation causes a bifurcation of the second tone with an emphasis on the pulmonary valve, and an increase in blood pressure in the systemic circulation causes a bifurcation and an emphasis on the aortic valve.

Splitting of heart sounds differs from bifurcation only in the degree of severity. With bifurcation, a pause between semitones clearly appears, and with splitting, the impression of tones with pre- or post-beats is obtained. The tone lengthens and seems to split in the middle.

Galloping rhythm. The gallop rhythm differs from the bifurcation in that it acquires a three-part character. This depends on a sharp split in tone, when the split-off part is perceived as a separate independent tone. The gallop rhythm is determined with rapid heartbeat; with physical stress it appears more clearly. The gallop rhythm can be presystolic, systolic and diastolic in nature.

The presystolic gallop rhythm is observed when the conduction of impulses along the His bundle between the atria and ventricles is difficult. This leads to a slowdown in ventricular excitation and the appearance of atrial sounds.

Rice. 22. Tonogram. Second tone splitting.

The gallop systolic rhythm is explained by the non-simultaneous contraction of the right and left ventricles and is based on conduction disturbances along the bundle branches or their branches.

The diastolic gallop rhythm is characterized by the appearance of an additional tone in the middle of a long pause, i.e. in the middle of diastole. This form has not yet been deciphered in relation to the mechanism of its occurrence. There is an assumption that the diastolic gallop rhythm is associated with the existence of a third tone (Obraztsov, Gubergrits). The existence of a third tone is supported by a graphical recording of a phonogram, which demonstrates small short-term fluctuations in diastole.

The appearance of the third tone is associated with fluctuations in the tension of the walls of the ventricles due to blood flowing into it during diastole. With a decrease in the tone and contractility of the ventricular muscle, the change in its tension under the pressure of blood will occur on a large scale, which is why the third tone becomes more sonorous.

The gallop rhythm indicates severe violations in the conduction system of the heart, associated with organic diseases heart muscle.

Embryocardia. For severe chronic failure heart rate and with its acute weakening, the pauses become of the same duration due to the shortening of the longer pause. In this case, heart sounds are compared according to the strength and nature of the sound. Differentiation of the first and second heart sounds becomes difficult. If cardiac activity also becomes more frequent, then in its nature it resembles the fetal heartbeat (embryocardia). Differentiation by cardiac impulse - coincidence of the first tone.

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Study of the circulatory system

The study begins with examination and palpation of the cardiac region, then percussion, auscultation of the heart, examination of blood vessels and instrumental and functional studies are carried out.

Inspection and palpation of the cardiac region. In healthy short-haired dogs, vibrations of the chest and hair in the heart area can be detected, and upon palpation, heart beats can be felt. Sometimes you can find increased sensitivity, soreness, palpable trembling, displacement of the push.

Palpation of the cardiac impulse is carried out, if possible, on standing animals, small dogs put on the table. The cardiac impulse is palpated on the left in the fifth intercostal space in the lower third of the chest. On the right it is weaker and appears in the fourth – fifth intercostal space.

Percussion (tapping) of the cardiac region. The zone of cardiac dullness in dogs is located in the third to sixth intercostal space. Absolute cardiac dullness of the heart is located in the fourth to sixth intercostal space. Its anterior border runs from the middle of the sternum parallel to the caudal edge of the fourth rib, then vertically to the costal joints, and its dorsal border horizontally reaches the sixth intercostal space, forming a curve curved backwards. Caudally it passes into the zone of hepatic dullness, and with midline chest - in the right-sided cardiac dullness in the fourth - fifth intercostal space 1-2 cm above the edge of the sternum.

Auscultation (listening) of the heart area. The study is carried out on standing animals, the thoracic limb is retracted forward. top scores obtained by auscultation on the left in the area of ​​the fourth - sixth intercostal space, on the right - in the fourth - fifth intercostal space. Normally, the first tone in dogs sounds duller, lower, louder, longer than the second tone, which is clearer, higher, less loud, shorter and abruptly ending. Pay attention to the frequency, rhythm, strength, clarity, timbre of tones, the presence of noise and their properties. Changes in heart sounds depend on the following main reasons and their combinations: change contractile function ventricles; change in valves; changes in pressure in the aorta or pulmonary artery; increasing the intervals between tone components. Their properties are influenced by the tissue covering the heart. Dogs normally have loud, clear, clear tones. Embryocardia is sometimes noted, especially in puppies.

Electrocardiography. Electrocardiographs are used to record ECGs. Using electrocardiography, the state of the functions of automaticity, excitability and conductivity is assessed, and arrhythmias, disorders of cardiac contractility (myocardial dystrophy, myocardial degeneration, cardiosclerosis), and intracardiac circulatory disorders (myocardial infarction) are identified.

Arterial examination. Inspect and determine arterial pulse, sphygmography, oscillometry, oscillography, tachometry and measurement of arterial blood pressure using special instruments.

Pulse in dogs They are examined through the femoral and brachial arteries, as well as through the saphenous artery. Count the pulse for 0.5–1 minute. The pulse rate in adult dogs is 70–120 beats per minute, in puppies – from 110 to 200 beats per minute. Most exact specifications obtained by recording the pulse.

Increased heart rate occurs with fever, excitement, injuries to the cardiac region, heart defects, pericarditis, endocarditis, and anemia. An increase in heart rate by 2.5 times is an unfavorable sign.

Counting heart beats

Pulse counting

A slowing of the pulse is observed in chronic myocarditis, digitalis poisoning, uremia, meningitis, cerebral hydrops, peritonitis, jaundice, in the convalescence stage, in exhaustion, myocardial degeneration, vagotonia - after the administration of vagotonic agents (arecoline, pilocarpine) and beta blockers (obzidan and its analogs ).

The quality of the pulse is assessed by the tension and filling of blood vessels, height and character pulse wave. According to voltage, soft, harsh, hard, hard and wiry pulses are distinguished; according to the degree of filling - full, moderate and empty; according to the size of the pulse wave - large, medium, small and thread-like; according to the shape of the pulse wave - normal, moderately falling, slow, jumping, alternating and false alternating pulse.

Arterial blood pressure(AKD). In dogs, ADC is determined on the femoral or brachial artery. To record blood pressure, oscillatory, palpatory and graphic methods are used. On the femoral artery the maximum arterial pressure is 165–185 mmHg. Art., minimum – 30–35, systolic – about 135–150 mm Hg. Art.; on the brachial artery – 120–140 and 30–40 mm Hg, respectively. Art., systolic (pulse) – 90–100 mm Hg. Art.

Vein research. During the examination, the filling of the veins is determined; venous pulse and venous blood pressure are examined, and if indicated, auscultation and venography are performed. The filling of the veins is determined by the relief of the vein pattern of the skin and conjunctiva, as well as by the condition of the jugular veins.

Negative (physiological, presystolic) venous pulse is manifested in the fact that when the jugular vein is compressed in the middle third of the neck, the vibrations of the vein disappear; positive (systolic, pathological) venous pulse - pulsation in the central and its cessation in the peripheral portion of the jugular vein with insufficiency of the right atrioventricular valve and atrial fibrillation.

Undulation manifests itself in the apparent pulsation of the jugular vein in the upper section when vibrations are transmitted to it from the carotid artery. Normally, it is absent and occurs with insufficiency of the semilunar valves of the aorta (racing pulse).

Heart rhythm disturbances (arrhythmias) are manifested in changes in the frequency, strength and sequence of heart contractions. They arise: when the automatism of the sinus node changes; when the impulse to contract the heart occurs heterotopically; if there is a violation of the conduction of impulses from the atria to the ventricles or inside the ventricles; due to impaired myocardial contractility. The genesis of arrhythmias in dogs is often based on complex disorders.

The study begins with an external examination, then examines the upper respiratory tract, accessory cavities, as well as the thyroid glands, chest using palpation, percussion, auscultation, pneumography, rhinoscopy, laryngoscopy, test puncture, as well as x-ray methods.

Examination of the upper respiratory tract. Pay attention to the properties of nasal discharge: quantity, transparency, consistency, smell and impurities. Outflows can be unilateral or bilateral. When bleeding from the lungs, the discharge is scarlet and foamy; blood is released from the upper respiratory tract in streams. The discharge may contain epithelium, pus, and in case of lobar pneumonia, fibrinous saffron-yellow casts from the bronchioles.

When examining the maxillary and frontal sinuses, the severity of external contours, symmetry, configuration, relief, volume, sensitivity, pain, local temperature, elasticity are determined bone walls, the presence of injuries and other defects.

Opening a dog's mouth

With pathology of the larynx and trachea, breathing difficulties may occur. With the help of palpation, you can determine swelling of the larynx, local increase temperature, pain, deformation of the arytenoid cartilages, fractures, ruptures of tracheal rings, changes in laryngeal and tracheal breathing. In order to internal research The larynx opens the mouth with the help of a yawn or ribbons.

The thyroid gland is palpated on the right and left in the area of ​​the first and third tracheal rings. The gland is normally painless, mobile, and elastic. Parathyroid glands are not detected upon palpation.

When examining a cough, one examines its strength, duration, pain, frequency, time and periodicity of occurrence, and the nature of the cough (low, muffled, sonorous, wet, dry, hoarse, stepwise).

Chest examination. Pay attention to the shape (narrow, ellipsoidal, round, barrel-shaped, long, short, normal) and symmetry of the chest, frequency, depth, strength and rhythm of breathing. These indicators should be assessed taking into account the breed, age, excitability, physiological state and other characteristics of the animals. The respiratory rate in dogs is 14–20 per minute.

Polyp (rapid) breathing is observed in febrile diseases, diseases of the peritoneum and pleura, heart failure, poisoning, heat and sunstroke. Oligopnea (slow breathing) more often occurs with diseases of the central nervous system (tumors, encephalitis, cerebral edema, hemorrhages), uremia, diseases of the digestive system, vagotonia.

The ratio of the inspiratory to expiratory phase in dogs is approximately 1:1.6. Breathing disorders of central origin are symptoms severe conditions. These include: saccadic breathing; the big breath of Kus-Maul; Biota breath; Cheyne-Stokes breathing; Grocco's dissociated breathing.

Frequent form respiratory failure shortness of breath (dyspnea) is inspiratory (inhalation), expiratory (exhalation) and mixed.

When palpating the chest, sensitivity, the presence of defects, fractures, resorption of ribs, and palpable vibration noises are determined. The percussion boundaries of the lungs along the line of the maculoca, ischial tuberosity and shoulder joint in dogs reach the twelfth, eleventh and ninth ribs. In healthy animals, the percussion sound is clear and pulmonary. In pathological cases it becomes dull, dull, tympanic, metallic or like the sound of a cracked pot. Establish the place, boundaries and features of these changes.

With the help of auscultation, the properties, nature and strength of sound phenomena occurring in the chest during breathing are revealed. The main respiratory sounds are normally caused by vesicular and bronchial breathing. Additional sound phenomena and changes in respiratory sounds occur when pathological processes in the lungs and pleural cavity. These include: pathological bronchial breathing; dry and wet wheezing; amphoric and bronchovesicular breathing; crepitus and pleural friction noises - splashing, bubbling and hissing.

To identify the nature and properties of the sweated chest cavity fluids use thoracentesis in the sixth - seventh intercostal space to a depth of 1-2 cm along the anterior edge of the rib, below the horizontal line of dullness formed by the fluid accumulated in the pleural cavity, and above the outer thoracic vein. The physicochemical properties and morphological composition of the effusion are examined.

They conduct an examination, study the intake of food and drink, examine the oral cavity, pharynx, esophagus, abdomen, stomach, small and large intestines, defecation, feces.

Examination of the oral cavity and esophagus. When examining the oral cavity, pharynx and esophagus, attention is paid to the condition of the mucous membranes of the lips, cheeks, gums, tongue, the integrity of the dental arcade, and its abrasion. The condition of the pharynx is determined by external and internal inspection and its palpation.

The esophagus is examined by inspection and palpation in the cervical part; chest part(if indicated) - by probing and x-ray.

The parotid and submandibular glands in healthy dogs are very poorly diagnosed. When inflamed, they change shape, size, consistency, become painful, and collateral edema occurs.

Abdominal examination. When examining the abdomen, inspection, palpation, percussion, and auscultation are performed. When indicated, a puncture is performed abdominal cavity, X-ray studies.

Determine the shape, volume, symmetry, contours of the abdomen, iliacs, integrity skin. When fluid accumulates in the abdominal cavity, deep palpation can reveal pain (peritonitis) or painless splashing of fluid (dropsy), the presence of chymostasis, coprostasis, flatulence, intussusception and volvulus.

A test puncture of the abdominal wall is carried out in the lower abdomen in the middle of the distance between xiphoid process and the navel 1–2 cm to the right or left of the white line to a depth of 1–2 cm.

Stool examination. Feces are subjected to macro- and microscopic, chemical and bacteriological research. At home with macroscopic examination pay attention to quantity, consistency, formation, digestion, color, smell and impurities.

Liver examination. The liver in dogs is accessible to palpation through the abdominal wall. Normally, it does not extend beyond the last rib, is painless, smooth, and has a dense consistency.

In case of acute enlargement of the liver, pain is determined by palpation and percussion. In chronic processes, atrophic cirrhosis, pain is mild or absent.

Spleen examination. In dogs, the spleen can be palpated through the abdominal wall. The animal is placed on its right side, the abdominal organs are lifted slightly upward with the left hand, and the spleen is located in the left hypochondrium with the right hand, paying attention to its size, density, pain and the nature of the surface.

Examine urination, external genitalia, kidneys, ureters, bladder, uterus, ovaries, oviducts, urethra. Conduct laboratory test urine.

Pay attention to the posture when urinating, the frequency of urges. Dogs excrete urine 3-4 times a day. With pathology, urination may be painful, frequent, infrequent, or stop completely. Urinary incontinence is sometimes noted.

With kidney pathology, renal (“flying”) edema occurs. With retention azotemia, the smell of urine in the exhaled air, depression, and drowsiness are noted.

In dogs left kidney palpated in the anterior corner of the hungry fossa under the second to fourth lumbar vertebrae, and the right one can sometimes be found under the first to third lumbar vertebrae.

When the bladder is full, cystitis, urolithiasis, or neoplasms, the volume, shape, consistency, and sensitivity of the bladder change. Additional data is obtained through catheterization, which also allows one to study the condition of the urethra. For urolithiasis and tumors, X-ray examinations are performed.

When studying physical properties urine is determined by its quantity, color, transparency, consistency, smell, relative density, and impurity content. The relative density of urine in dogs is 1.020–1.025, it increases with a decrease in water consumption, excisosis, fever and decreases with a decrease in the reabsorptive function of the kidneys (glomerulonephritis, nephrosclerosis).

The chemical composition of urine is determined by laboratory testing.

They study the behavior of the animal, the condition of the skull and spine, sensory organs, motor and sensory spheres, reflexes, the autonomic nervous system, as well as cerebrospinal fluid ( brain fluid). Depression can occur in the form of apathy, stupor, stupor and coma. Excitement manifests itself as excessive motor activity, violence, aggressiveness.

When examining the skull and spine, pay attention to the following indicators: volume, shape, structure of the skull and its individual parts; integrity of the bone skeleton; sensitivity, resistance of bones to pressure, presence of disorders of the supporting-static function of the spine.

When examining the organs of vision, the pathology is manifested by infiltration of the eyelids, protrusion, retraction eyeball, strabismus, nystagmus, constriction or dilation of the pupil, inflammation or clouding of the cornea. Cloudiness, inflammation of the retina, and atrophy may be present in the fundus of the eye. optic nerve. Blindness (amaurosis) or decreased vision (amblyopia) is detected when the dog is guided through obstacles. Auditory and taste perception and smell can be hypersthetic, normal, weakened or completely lost.

The study of the sensitive sphere includes the study of exteroceptive (superficial), proprioceptive (deep), and metameric sensitivity. Disorders of tactile, pain and temperature sensitivity manifest themselves in the form of hypoesthesia, anesthesia, hyperesthesia, hypoalgesia, analgesia, hyperalgesia, tasthhypoesthesia, tastanesthesia, tasthhyperesthesia, thermoanesthesia and thermohyperesthesia.

The decrease and loss of surface sensitivity can be local, unilateral (hemianesthesia), bilateral (paraanesthesia). Increased skin sensitivity has central and peripheral origin. Pain can be reactive (voluntary), involuntary, local, projected, radiating and reflected. Proprioceptive sensitivity is detected through ligamentous, articular, tendon and bone reflexes.

When researching motor sphere pay attention to muscle tone (hypertension, normotonia, atony) and passive movements. Impaired motor coordination can be expressed in the form of static or dynamic ataxia. There are peripheral, vestibular, cerebellar and cerebral ataxias.

With paresis, the ability for active movements is sharply limited, and with central (spastic) and peripheral (flabby) paralysis, it is lost. Paralysis includes mono-, hemi-, and paraplegia.

Clonic and tonic hyperkinesis have central and peripheral origin. Clonic seizures manifest themselves in the form of convulsions, tremor, nystagmus, tic, fibrillation, and tonic (tetanic) - in the form of tetanus, trismus, crump, contracture of the back of the head. When the nervous system is damaged, epileptic seizures may occur, and the electrical excitability of muscles and nerves changes.

Among the skin reflexes, the most important are the abdominal, anal and ear ones; among the reflexes of the mucous membranes - conjunctival, corneal, sneezing; Among the deep reflexes are the knee and Achilles.

Changes in reflexes manifest themselves in the form of their weakening, loss, distortion or strengthening.

For special indications, physicochemical, bacteriological and morphological analysis of cerebrospinal fluid obtained by suboccipital or cervical puncture is performed.

First aid and disease prevention

Sometimes you can already judge at first glance general state animal and correctly assume the diagnosis. Depending on the degree of disorder, the dog may exhibit the following symptoms:

Shock – a life-threatening condition characterized by severe disorders of the central nervous system, blood circulation, respiration and metabolism, caused by the action of an extremely strong pathological irritant on the body.

Stupor– a state of stunning observed during concussions and poisoning.

Sopor- hibernation that occurs during infectious diseases, in initial stage uremia. From this state, a sick animal can be brought to a short time loud shout, while reflexes are preserved.

Coma- an unconscious state characterized by complete absence reactions to external stimuli, lack of reflexes and disorders of vital functions.

Lameness on the thoracic limb– in shepherd dogs it is almost always caused by dysplasia in the elbow joint.

Lameness in the pelvic limbs– in shepherd dogs indicates dysplasia hip joints and deforming coxarthrosis, in boxers - about pathology in knee joints(cruciate ligament rupture, meniscal damage). Lameness in one of the pelvic limbs in poodles, Pekingese or Spitz dogs may be caused by a dislocated kneecap.

Paresis of the pelvic limbs(partial or complete) – in dachshunds, poodles, Pekingese, spaniels and French bulldogs caused by prolapse of intervertebral discs.

For lacrimation One can assume conjunctivitis, keratitis, pathological growth of eyelashes along the edge of the eyelid, inversion or eversion of the eyelids, obstruction of the nasolacrimal duct.

Salivation most often caused by inflammation in the oral cavity or oropharynx. If the dog scratches its head at the same time, as if trying to free itself from something, then one should suspect a hit. foreign body. Excessive drooling may also be observed in cases of poisoning.

Cough may be caused by collar pressure. In this case, one should assume inflammation of the throat, larynx or trachea, diseases of the lungs and heart. A sudden, severe, persistent cough can be caused by a foreign body entering the trachea.

Eye examination

Enlarged belly. This is normal when pregnant physiological state. In other cases, abdominal hydrops, tumors, or pyometry can be suspected. Sudden bloating, commonly seen in dogs large breeds, occurs due to acute dilation, volvulus of the stomach or rupture of its wall.

Unpleasant smell mouth in spaniels is often caused by eczema located in the folds of the lips. In other dogs, as a rule, this is a consequence of abundant deposits of tartar with ulcerative stomatitis, a decaying tumor; one can also assume the presence of a foreign body in the oral cavity or oropharynx. An unpleasant odor comes from a dog when neglected purulent otitis(inflammation ear canal). Skin lesions with demodicosis have an unpleasant smell.

Smell of urine or acetone points to severe form uremia and progressive diabetes with ketosis.

Forced position animal due to illness. Healthy dog usually sits or sleeps in a relaxed position, with the body straight and limbs extended. A sick animal takes forced situation, weakening or stopping his painful sensations. For example, with abdominal pain, the dog bends the spine and strongly presses the pelvic limbs towards the stomach; for heart disease, stands in a position with elbows wide apart to relieve breathing movements; in case of damage to a limb, it holds it suspended.