The Abdomen 247 



Exostoses of the penial bone are removed by exposing the bone 

 by cautious dissection without injuring the urethra, and removing 

 them with suitable forceps. 



OBSTEUCTION. 



This usually takes place from the lodgment of calculi, but may 

 also be occasioned by the parasitic giant Eustrongyle. 



Calculi. (See also Urolithiasis.) It will be remembered 

 that in the male the Urethra is narrow in its prostatic portion, be-; 

 comes widest in its membranous portion, and again narrow as it 

 passes into the cavernous portion, while it loses all power of ex- 

 pansibility as it traverses the gutter of the penial bone. Sediment 

 and the smaller stones very frequently pass into the urethra and 

 lodge at one of the narrower points and form an obstruction. This 

 takes place most frequently at the proximal extremity of the penial 

 bone, and also occasionally just anterior to the prostatic portion. 

 These stones may be present as an impacted mass of numerous 

 small calculi, cemented together by mucus, and extending some dis- 

 tance up the lumen of the canal. They often become embedded in 

 the wall. Siedamgrotzky described a case of a three months' old 

 animal which died suddenly suffering from inflammatory edema of 

 the foreskin. He found a cylindrical calculus in the curved portion 

 of the urethra, the latter having been perforated by it, thereby 

 causing infiltration of urine. Tuffier found calculi in the prostatic 

 portion of the urethra. 



Exostoses of the penial bone produce the effect of urethral cal- 

 culi and may be mistaken for the latter. 



In the female also calculi sometimes lodge in the urethra, but 

 this seldom takes place owing to the larger caliber, shortness, and 

 dilatability of the canal. 



Lodgment of calculi in the urethra causes damming back of 

 the urine in the bladder, which extends to both kidneys and results 

 in bilateral hydronephrosis and rapid dissolution. It is rare that 

 the bladder ruptures, owing to the compensatory hypertrophy which 

 it undergoes. Petit and Almy have recorded an instance. The ex- 

 tremity of the penis may also become gangrenous. 



Symptoms and Diagnosis. The symptoms are very marked. 

 The animal is exceedingly uneasy, lowers its head, looks round at 

 the flanks, arches its back, assumes a straddling gait or posture like 



