Veterinary Clinical Medicine-I (General and Systemic)

AUSCULTATION

Principles

• In auscultation the physician listens to the sounds generated in the organs. There are two methods of auscultation.
  • Immediate auscultation placing the ear directly against the chest wall and
  • Mediate auscultation listening through an instrument.
• Because of poor acoustic impendance matching, the frequency response of an ordinary stethoscope is not ideal. So a Phonendoscope is to be employed in large animal practice. Further the phonendoscope can amplify even the faint pathological sounds which no stethoscope can do.

Phonendoscope

• It was invented by Bazzi a Physicist and Bianchi a physician initaly in 1810.
• The advantage of this instrument is the double diaphragm which helps in the precise localizations and amplification of faint sounds.
• Modern phonendoscopes have one chest piece with a shell-acoustic stiff diaphragm with a rubber beading suitably designed to make the animal’s skin to act as the second diaphragm. The stiff diaphragm is an important feature of the phonendoscope.
• Chest piece is connected by two metal tubes at specific angles to amplify the sounds instead of one in stethoscope.
• The double diaphragm system enable the clinician to identify the functional sounds arising from restricted areas such as heart valves in large animals. The rubber also minimizes frictional sounds.
• The following organs are auscultated in large animals using a phonndoscope.
  • Heart
  • Treachea
  • Bronchi
  • Lungs
  • Rumen
  • Reticulam
  • Omasum
  • Abomasum and
  • Intestine
• However, the region should first be thoroughly moistened or oiled to avoid materially interfering hair coats.