Veterinary Clinical Medicine-I (General and Systemic)

RESPIRATORY SOUNDS ON AUSCULTUTION

• The normal respiratory sound heard over the respiratory area consists of vesicular sound & bronchial sound.

• Vesicular respiratory sound "vesicular murmur" The vesicular murmur resemble the sound produced when the letter "V" is whispered softly & it occurs during inspiration, but during expiration the vesicular murmur changes its character& resembles the sound of the letter "F".
• The vesicular murmur may be exaggerated or feeble "soft".

Exaggerated vesicular sound

• Increased respiratory frequency "polypnea".
• Increased depth of respiration "hyperpnea".
• Occurs normally in young animals.

Feeble vesicular sound

• Thickening of thoracic wall & pleura due to any cause
• Reduced air content of the lung as in early stages of pneumonia.
• In old animals.
• Hydrothorax, hemothorax & pulmonary neoplasms.

Bronchial respiratory sound

• It resembles the sound produced by the letter "CH". It is heard clearly in small animals and very lean old animals but in large animals it is less distinct.

• The occurrences of bronchial sound in the lung are indicating of a diseased condition.
• It is audible when the lung contains less air with increase in the structural density of the inflammatory area which acts as a good conductor of the sound as in cases of hydrothorax, hemthorax & pleurisy "Exudative stage".
• Cripitant rales
  • Occurs when the bronchial mucosa is sufficiently swollen & affection extends to involve the alveoli. So, opposing walls become adherent to one another but the stream of air still pass through small communication between them it resembles the sound produced by rubbing a tuft of hair held between fingers close to the ear. It occurs in cases of:
    • Bronchiolitis.
    • Early stages of pneumonia.
    • Pulmonary odema.

Frictional sound

• Normally the visceral & parietal pleura glide smoothly over each other, since both membranes are smooth & lubricated by clear lymph like fluid, when these surfaces are dry, frictional sound occurs.
• It resembles the sound produced by rubbing two pieces of leather against each other or by pressing the finger against the ear & stretching the finger nail of other hand. It occurs in cases of:
  • Preexudative stage of pleurisy.
  • Pericarditis.

Emphysematous sound (Harch sound), or (Sharp sound)

• Resembles the sound produced by collection of a piece of paper between fingers & hand.

Girgling sound

• Resembles sound produced by gases & air bubbles, as in cases of diaphragmatic hernia (in the chest) &bloat (in the rumen).
• Moist rales: Occurs when the bronchi & bronchioles contains thin watery mucous secretions, they are obtaining as when air is drawn from the end of the tube under the surface of water, so it is called bubbling sound. According to the site of affection moist rales are classified into:-
  • A-Fine moist rales : Occurs when the terminal parts of respiratory tract "alveoli" are involved. They are of unfavorable prognosis.
  • B-Coarse moist rales : Occurs when the affections are confined to the bronchi & bronchioles only. It occurs in cases of:
    • Bronchitis "acute".
    • Bronchiolitis.
    • Bronchopneumonia.
    • Aspiration "drenching pneumonia".
    • Hydrothorax.
    • Haemothorax.
    • Exudative stage of pleurisy.
• Dry rales
  • Dry rales are heard when air is forced through the bronchial tube which is partially thickened by the thick consistency exudate as by the severe swelling of the mucous membrane. It resembles the sound produced by the movement of two tightly stretched papers against each other. It occurs in cases of:
    • Early acute stages of bronchitis.
    • Chronic bronchitis.
    • T.B