876 CATTLE 



the belly. In examination and in operation for stone inHhe bladder, 

 this should not be lost sight of. It has three coats : the outer and 

 peritoneal ; the central or muscular, and the inner coat, which is 

 lined with numerous glands, that secrete a mucous fluid in order to 

 defend the bladder from the acrimony of the urine. 



The bladder terminates in a small neck, aronnd which is a continua- 

 tion of the common muscular coat, or, in the opinion of some, a dis- 

 tinct circular muscle, the sphincter, whose natural state is that of 

 contraction ; so that the passage remains closed, and the urine re- 

 tained, until, the bladder being stretched to a certain extent, the 

 fluid is expelled either by the will of the animal, or the involuntary 

 contraction of the muscular coat. This muscle is weak in the ox. 

 Advantage may be tak*>n of this weakness of the sphincter muscle, 

 for in retention of urine, or when, for the purpose of some operation, 

 it may be expedient to empty the bladder, the slightest pressure 

 upon it by the hand introduced into the rectum will readily effect it. 



Having passed the sphincter muscle, the urine flows through the 

 urethra and is evacuated. This canal is long and small ; it pursues 

 a tortuous path. The peculiar form and direction of some of the 

 muscles of that region compel the penis to take a kind of double 

 curve, not unlike an aS', before it takes its ultimate straight course ; 

 and on these accounts the ox suffers occasionally from the entangle- 

 ment of calculi in the folds of the urethra. 



The bladder of the cow is smaller and rounder than that of the 

 ox. The rumen is as large as in the ox, and occupies the greater 

 part of the abdomen ; but additional room must be left for the im- 

 pregnated uterus, and that is effected in some measure at the expense 

 of the bladder ; while also, to obviate the ill effects of occasional 

 pressure in the distended state of the uterus, the sphincter muscle at 

 the neck of the bladder of the cow is much larger and stronger than 

 the same muscle in the ox. 



The circumstances of disease to be considered with reference to 

 the bladder are the foreign bodies, principally calculi, which it may 

 contain ; the inflammation resulting from that or from other causes ; 

 rupture, and inversion of it. 



URINARY CALCULI. 



Concretions are found in the urinary passages of cattle. One 

 cause of their retention may be the form of the passages. Many 

 calculi are retained in the bladder, and thus become the centre 

 around which other matter collects, layer upon layer. It it probably 

 on this account that calculi are found so much oftener in the ox than 

 the cow ; in the former the urethra is long and small, in the latter it 

 is short and capacious. 



The great function discharged by the kidney in catfle may like- 

 wise account for the more frequent formation of calculi. When so 



