120 



CLINICAL DIAGNOSTICS. 



may be defined by a line which in tlie larger animals is the width 

 of a hand from the points of insertion of the diaphragm. In 

 small animals the distance is one-half this. 



The availableness of the lungs for clinical examination. 

 Dorsally the area of percussion is defined by the thick muscles 

 of the back. This boundary to percussion, which varies with 

 the condition of the animal, is limited by a line drawn from the 

 posterior angle of the scapula to the external angle of the ilium. 

 Anteriorly the boundary is formed by the scapula and the 

 massive shoulder muscles. 



Fig. 34. 

 Heart, shaded portion not covered by lung. — Field of pulmonary percussion. 

 — - — Insertion of diapragm. L. Liver. M. Spleen. N. Kidneys. 

 R. Rectum. D. Small intestines. 



By drawing the leg forward the field of percussion can be 

 somewhat enlarged. Vcntrally the density of the sternum and 

 muscles overlying it render in this region the lungs unavail- 

 able to percussion. 



The field of percussion is a right-angled tri- 

 angle the right angle of which lies at the 

 base of t h e s c a p u 1 a . In all animals the dorsal and 

 anterior boundaries of the field of percussion are the same, the 

 only variation being in the abdominal boundary. 



