INSPECTION

Inspect the patient while obtaining the history. Perform the inspection while the animal enters the room; while the pet stands, sits, or walks; while the owner supports the pet; and while the pet stands alone.

Condition, Attitude, and Posture

• Body condition of the patient is classified according to the degree of fat.

• Normal overweight animals usually are not ill from heart failure but may manifest signs caused by pulmonary disease (e.g., chronic obstructive lung disease, pulmonary fibrosis).

• Animals with moderate to long-standing heart failure are often thin to cachectic.

• Attitude of an animal with heart failure is usually depressed.

• Posture of animals with heart failure is often:

• Standing—reluctant to lay down—with thoracic limbs abducted and neck extended to ease ventilation.

• Swayback with the tail between the legs because of muscular weakness or occasionally caused by digitalis toxicity (from overdosage or impaired renal excretion related to dehydration or primary renal disease). Swayback can also result from electrolyte imbalance—in particularhypokalemia—caused by prolonged or excessive use of diuretics without consumption of sufficient electrolytes.

• Dogs with cardiomyopathy often have weakness of skeletal muscles and dogs with heart failure are often exhausted owing to the work of breathing.

Mucous Membrane Color

• Mucous membranes may be pink, pale, or cyanotic.

• Normal mucous membranes have a deeply saturated pink color. Gentle pressure on the gums will lead to blanching (whiteness) of the membranes. The capillary refill time needed to regain normal coloration is about 2 seconds or less.

• Delayed refill time generally indicates peripheral vasoconstriction, often as a compensatory response to reduced arterial blood pressure.

• Bright red membranes associated with a very short refill time may indicate peripheral vasodilation, as might occur with septic shock or during treatment with potent arterial vasodilator drugs.

• Mucous membranes are pale in some patients. Pallor indicates anemia or low cardiac output with reflex vasoconstriction (e.g., low output heart failure, severe aortic stenosis, cardiac tamponade), but without pulmonary congestion that often causes cyanosis.

Cyanosis

Cyanosis indicates the finding of dark-blue to purple colored mucous membranes caused by poorly oxygenated (desaturated) hemoglobin. The main reasons for cyanosis are respiratory disease and right-to-left shunting due to congenital heart disease.

• Methemoglobinemia (congenital or acquired from drug toxicity) may also alter the color of the mucous membranes.

• Cyanosis to the mucous membranes may be observed in late stages of congestive heart failure or in puppies or young dogs with tetralogy of Fallot or other congenital heart defects with right-to-left shunts. (see Chapter 154)

• Cyanosis occurs much more commonly in all types of pulmonary disease.

• Mucous membranes may be dark red in stages just prior to frank cyanosis.

• Long-standing cyanosis most commonly indicates pulmonary disease, since an animal cyanotic from heart disease usually either dies from the severity of the disease or the cyanosis is relieved with therapy.

Pattern of Ventilation

Observing the pattern of ventilation is extremely important. Characterize the rate and depth of breathing, and identify dyspnea.

• Rate of breaths per minute should be between 12 and 20 for dogs and only slightly higher for cats, but may increase from excitement, fever, anxiety, warm environment, chronic respiratory disease, respiratory failure, left-sided heart failure, or pulmonary injury.

• Depth of ventilation is difficult to quantify, but hyperpnea (increased depth) is often a sign of blood gas derangement (e.g., response to metabolic acidosis). It is not often observed in heart disease except with severe pulmonary edema. In upper airway obstruction both the inspiratory and expiratory phases of ventilation may become slower and exaggerated. In pleural diseases, the depth is generally shallow and the rate rapid. An exaggerated expiratory phase is typical of bronchial obstruction.

• Pulmonary retraction is an indention of the thoracic wall caused by fatigue of muscles of ventilation. Regions of the thoracic wall affected must generate greatest tension during ventilation and do not have assistance from thoracic limbs. Pulmonary retraction produces an “hourglass” configuration to the thorax (most evident when viewing the dorsoventral radiograph).

Cough

Cough is a sign of both heart and lung disease. It may be characterized as follows:

• A hacking, honking, brassy cough indicates disease of the large airways, such as tracheobronchial collapse, compression of the left mainstem bronchus due to mitral regurgitation or generalized cardiomegaly, tracheobronchitis, or bronchopulmonary parasitism. This type of cough is seldom due to injury of the parenchyma of the lung and therefore is uncommon in pulmonary edema or pneumonia.

• Subtle or “half-hearted” coughing may be caused by pulmonary edema, pneumonia, or diaphragmatic hernia.

• So-called moist or truly productive coughs usually indicate an exudative process; however, in late stages of left-sided congestive heart failure it is common to have serosanguineous pulmonary edema fluid expectorated to gush from the nares and/or mouth.

Jugular Vein Evaluation

Analysis of the jugular vein (Fig. 142-1) is simpler if the hair is clipped from around the jugular furrow or if it is moistened with 70% alcohol. Look for pulsations in the vein and estimate the pressure distending it.