150 DISEASES OP CATTLE. 



tinct pouch, in which this unctuous matter is liable to accumulate when 

 the penis is habitually drawn back. Moreover, the sheath has two mus- 

 cles (protractors) which lengthen it passing into it from the region of 

 the navel, and two (retractors) that shorten it passing into it from the 

 lower surface of the pelvic bones above. (PI. IX, fig. 2.) The pro- 

 tractors keep the sheath stretched so that it habitually covers the 

 penis, while the retractors shorten it up in the act of service, so that 

 the penis can project to its full extent. In stud bulls the frequent 

 protrusion of the erect and enlarged penis and the retraction and 

 dilatation of the opening of the sheath serve to empty the pouch and 

 prevent any accumulation of sebaceous matter or urine. In the ox, 

 on the other hand, the undeveloped and inactive penis is usually 

 drawn back so as to leave the anterior preputial pouch empty, so that 

 the sebaceous matter has space to accumulate and is never expelled by 

 the active retraction of the sheath and protrusion of the erect penis 

 in service. Again, the ox rarely protrudes the tip of the penis in 

 urination, the urine is discharged into the preputial pouch and lodges 

 and decomposes there, so that there is a great liability to the precipi- 

 tation of its earthy salts in the form of gravel. The decomposing 

 aminoniacal urine, the gritty crystals precipitated from it, and the 

 fetid, rancid, sebaceous matter set up inflammation in the delicate 

 mucous membrane lining the passage. The membrane is thickened, 

 reddened, rendered friable, and ultimately ulcerated, and the now 

 narrowed sheath is blocked by the increasing mass of sebaceous and 

 urinous material and the decomposing mucus and pus. The penis 

 can no longer be protruded, the urine escapes in a small stream 

 through the narrowing sheath, and finally the outlet is completely 

 blocked and the urine distends the back part of the sheath. This 

 will fluctuate on being handled, and soon the unhealthy inflammation 

 extends on each side of it, causing a thick, doughy, tender swelling 

 under the belly and between the thighs. The next step in the morbid 

 course is overdistention of the bladder, with the occurrence of col- 

 icky pains, looking at the flanks, uneasy movements of the hind 

 limbs, raising or twisting of the tail, pulsatory contractions of the 

 urethra under the anus, and finally a false appearance of relief, which 

 is caused by rupture of the bladder. Before this rupture takes place 

 the distended bladder may press on the rectum and obstruct the pas- 

 sage of the bowel dejections. Two mistakes are therefore probable — 

 first, that the bowels alone are to be relieved, and, second, that the 

 trouble is obstruction of the urethra by a stone. Hence the need of 

 examining the sheath and pushing the finger into its opening to see 

 that there is no obstruction there, in all cases of retention of urine, over- 

 distended bladder, or blocked rectum in the ox. The disease may be 

 acute or chronic — the first by reason of acute adhesive inflammation 

 blocking the outlet, the second by gradual thickening and ulceration 

 of the sheath and blocking by the sebaceous and calculous accretions. 



