DIGESTIVE APPARATUS. 161 



character of the contents of the various sections of the intes- 

 tinal tract. 



As a rule the stomach and intestines contain a moderate 

 quantity of gases which distend their walls only slightly; 

 hence percussion produces a tympanitic sound. In the paunch 

 of cattle and the large intestine of the horse where food 

 masses accumulate, the sound is at times dull tympanitic or 

 even dull. (Topography of bowels at left side in the horse; 

 see Fig. 32.) 



Abnormal . accumulations of food masses in the cecum 

 and colon give rise to a dull sound and a sensation of resist- 

 ance to the- finger or pleximetric hammer at points on the ab- 

 dominal wall Opposite them. If the accumulation of gases 

 causes the bowel , walls to' distend abnormally and become 

 tense, a clear sound is produced, a sound resembling that pro- 

 duced by the healthy lung, only clearer and louder because 

 large air chambers are present. (In the lungs the air cham- 

 bers are small) ; - 



Bilateral dullness, limited above by a horizontal line, is 

 observed when fluids collect in the abdomen (ascites). This is 

 most frequent in the dog; raising the animal to a vertical 

 position shifts the dull area accordingly. 



d. Auscultation of the abdomen. The observation of 

 the various sounds produced by the moving along- of the intes- 

 tinal contents has for its object the determination of the char- 

 acter of the movements of the bowels. The sounds are pro- 

 duced by the onward movement of the solid, liquid and gaseous 

 contents of the bowels. The gases particularly produce dis- 

 tinctly audible sounds. In the absence of _ intestinal contents 

 sounds are not produced by peristaltic motion. 



The character of the sounds is determined by the consist- 

 ency of the intestinal contents and by the quantity of gases 

 present. Hence: the sounds of the small intestine are those 

 of flowing liquid, gurgling, and splashing; the sounds of the 

 'arge intestine rumbling, cooing, and tumbling. 



