CYSTOCENTESIS 69 



bladder be not so enormously distended as to expose it to 

 rupture. 



Veterinarians practicing where urinary calculi are com- 

 mon in cattle frequently find it necessary to resort to the 

 operation under some of these circumstances. Amongst 

 horses these indications are not uncommon. . 



The bladder, in complete urethral obstruction, by distend- 

 ing under pressure of the constant entrance of urine, becomes 

 stretched out of all ordinary proportions. Its capacity may 

 increase to a point that is almost beyond comprehension. It 

 may extend anteriorly as far as the liver, downward as far as 

 the floor of the abdomen and posteriorly it may obstruct the 

 pelvic lumen before the walls give way to the pressure, but 

 usually in the horse and the ox a rupture of the urethra will 

 occur at a point near to the obstruction long before the organ 

 assumes such enormous proportions. In the dog a distended 

 bladder, by enlarging the dimensions of the abdomen, may 

 produce symptoms analogous to ascites. The two . condi- 

 tions are not easily differentiated. Even in making an ex- 

 ploratory puncture the nature of the fluid may escape atten- 

 tion. 



The symptoms of complete urethral obstructions at first 

 consist of repeated unsuccessful attempts to micturate; later 

 the straining becomes forcible and continuous, but finally 

 after several days it discontinues and no further attempt is 

 made to evacuate the over-distended .organ which now being 

 paralyzed is no longer capable of conveying the necessary 

 impulse. The symptoms henceforth are general, consisting 

 of an accentuating emaciation, poor appetite, anxious eyes, 

 slight fever and a more or less labored breathing. The strain- 

 ing, if any, is an occasional attempt to defecate rather than to 

 urinate; the distended and paralyzed bladder compresses the 

 rectum, which then conveys the wrong impulse. 



The diagnosis in the larger animals is never difficult. The 

 straining during the first few days, or a history that such 

 straining to urinate has existed, followed by an investigating 

 rectal examination, at once reveals the nature of the abnor- 

 mality. 



EQUIPMENT. — The only instrument required to per- 

 form the operation is an ordinary intestinal trocar and canula 

 and a piece of soft rubber tubing that will fit easily over the 

 canula after the trocar is withdrawn. The tubing is not ab- 

 solutely necessary, as the urine will flow into and then out of 

 the rectum without such an attachment. It is, however, ad- 



