DISEASES OF THE HORSE. 103 



ing 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 surface 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 urethi-a beneath the anus. In any case the 

 urethra betvreen the neck of the bladder and the point of obstruction 

 is likely to be filled with fluid, and to feel like a distented tube fluctu- 

 ating on pressure. 



Treatment of urethral calmihis 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 pointed forceps and withdrawn from the urethra; or, if necessary, a 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 

 (protractile) portion of the penis, that organ is to be withdrawn from 

 its sheath until the nodule is exposed and can be incised. If behind 

 the scrotum, the incision must be made in the median line between the 

 thighs and directl}^ over the nodule, the skin having been rendered 

 tense by the fingers and thumb of the left hand. If the stone has been 

 arrested in the intrapelvic portion of the urethra, the incision must be 

 made beneath the anus and the calculus extracted with forceps, as in 

 stone in the bladder. The wound in the urethra may be stitched up, 

 and usually heals slowly but satisfactoril3^ Healing will be favored 

 hy washing two or three times daily with a solution of a teaspoonful 

 of carbolic acid in a pint of water. 



Preputial calculus {calculus in the sheath, or Mlocular cavity). — 

 These are concretions in the sheath, though the term has been also 

 applied to the nodule of sebaceous matter which accumulates in the 

 blind pouches (bilocular cavity) by the sides of the papilla on the end 

 of the penis. Within the sheath the concretion may be a soft, cheesy- 

 like sebaceous matter, or a genuine calculus of carbonate, oxalate, 

 phosphate and sulphate of lime, carbonate of magnesia, and organic 

 matter. These are easily removed with the fingers, after which the 

 sheath should be washed out with castile soap and warm water, and 

 smeared with sweet oil. 



