162 DISEASES OF THE HOKSE. 



To prevent the formation of a new deposit any fault in feeding 

 (dry grain and hav with privation of water, excess of beans, peas, 

 wheat bran, etc.) and disorders of stomach, liver, and lungs must 

 be corrected. Give abundance of soft drinking water, encouragmg 

 the animal to drink by a handful of salt daily. Let the feed be laxa- 

 tive, consisting largely of roots, apples, pumpkins, ensilage, and give 

 daily in the drinking water a dram of either carbonate of potash or 

 soda. Powdered gentian root (3 drams daily) will also serve to 

 restore the tone of the stomach and system at large'. 



Urethral calculus {stone in the urethra) .—This is less frequent in 

 horses than in cattle and sheep, owing to the larger size of the urethra 

 in the horse and the absence of the S-shaped curve and vermiform 

 appendix. The calculi arrested in the urethra are never formed 

 there, but consist of cystic calculi which have been small enough to 

 pass through the neck of the bladder, but are too large to pass 

 through the whole length of the urethra and escape. Such calculi 

 therefore are primarily formed either in the bladder or kidney, and 

 have the chemical composition of the other calculi found in those 

 organs. They may be arrested at any point of the urethra^ from the 

 neck of the bladder back to the bend of the tube beneath the anus, 

 and from that point down to the extremity of the penis. I have 

 found them most frequently in the papilla on the extreme end of the 

 penis, and immediately behind this. 



Symptoms of urethral calculus. — The symptoms are violent strain- 

 ing to urinate, but without any discharge, or with the escape of water 

 in drops only. Examination of the end of the penis will detect the 

 swelling of the papilla or the urethra behind it, and the presence 

 of a hard mass in the center. A probe inserted into the urethra will 

 strike against the gritty calculus. If the stone has been arrested 

 higher up, its position may be detected as a small, hard, sensitive 

 knot on the line of the urethra, in the median line of the lower sur- 

 face of the penis, or on the floor of pelvis in the median line from 

 the neck of the bladder back to the bend of the urethra beneath the 

 anus. In any case the urethra between the neck of the bladder and 

 the point of obstruction is liable to be filled with fluid, and to feel 

 like a distended tube, fluctuating on pressure. 



Treatment of urethral calculus may be begun by an attempt to 

 extract the calculi by manipulation of the papilla on the end of the 

 penis. This failing, the calculus may be seized with a pair of fine- 

 pointed forceps and withdrawn from the urethra ; or, if necessary, a 

 probe-pointed knife may be inserted and the urethra slightly, dilated, 

 or even laid open, and the stone removed. If the stone has been 

 arrested higher up it must be extracted by a direct incision through 

 the walls of the urethra and down upon the nodule. If in the free 



