The operation of lithotripsy or crushing may be resorted to when the stone, though too large to be moved entire, is yet small enough to be seized and broken up into fragments by means of the lithotrite. In the quadruped it is not performed as in man, through the natural channel of the urethra, but through an artificial opening in the urethral canal as described in the operation of lithotomy. It must, therefore, always be regarded as supplementary to lithotomy, and depend for its performance on our inability to extract the calculus whole.

In the absence of serious complications lithotripsy offers a fair and reasonable prospect of success.

If from the first the operation is found to be necessary, the bowels should be freely opened with an aloetic purge, and the diet so ordered as to avoid undue fulness of the alimentary canal, and facilitate digestion. An enema of warm water administered once or twice during the twenty-four hours before its performance will serve to keep the rectum empty and soothe the irritable bladder. Small doses of potassic bicarbonate, and opiates, if necessary, may be given at intervals where pain is indicated.

Drainage Tube A, Silver mount and rings. B, Elastic gum tube.

Fig. 156. - Drainage Tube A, Silver mount and rings. B, Elastic gum tube.

Perineal Needle.

Fig. 157. - Perineal Needle.