146 CLINICAL DIAGNOSTICS. 



abdomen in domesticated animals is subject to great variations 

 and great care must be exercised here in diagnosis. For clini- 

 cal purposes the size of the abdomen must always be con- 

 sidered in connection with the general condition of the animal, 

 its general make up. feed, care. etc. Animals habitually kept 

 on voluminous food in ample abundance develop a voluminous 

 abdomen. A good plan is to inquire of the owner as to the 

 former or usual condition of the animal in this respect. Cir- 

 cumscribed enlargements are usually of interest from a sur- 

 gical point of view. 



Abnormal distention of the abdomen may be due to: 



1. Pregnancy ; the form of the abdomen becomes barrel 

 shaped — increasing bilaterally. 



2. Accumulation of abnormal quantities of food in the 

 digestive tract (in horses the cecum and colon, in ruminants 

 the paunch and other stomachs, in dogs the stomach ) . In 

 these cases the distention is due either to increased consump- 

 tion of food (overfeeding) or to accumulation of food taken 

 in normal quantities during inactivity of the bowels (constipa- 

 tion). In these cases the normal tympanitic tone is replaced 

 by a dull one. 



3. The accumulation of gases produced by fermenting 

 food. In this case the distention is in an upward direction, 

 the hollow of the flank is raised, and the abdominal walls be- 

 come distended (tympanitis, bloat). The rapid production of 

 gas may be due to the character of the food [legumes, cruci- 

 fera, etc.] or to suspended activity of the bowels. 



4. Accumxdatio)i of fluid (transudate and exudate) in 

 the peritoneal cavity. This is occasionally seen in dogs, rarely 

 in horses. In this case the distention is in a downward direc- 

 tion, symmetrical and bilateral, fluctuation is observed and 

 percussion reveals a dull area bounded above by a horizontal 

 line. When a dog thus affected is raised to a vertical position 

 ihe dull area is shifted (ascites). 



