Occasionally the pressure of the bladder on the calculus which it contains is exceedingly great, so much so, indeed, as to crush the calculus. A small calculus may sometimes be forcibly extracted, or cut down upon and removed; but when the calculus is large, a catheter or bougie must be passed up the penis as far as the curve in the urethra, and then somewhat firmly held with the left hand, and pressing against the urethra. A scalpel should be taken, and an incision made into the urethra. The catheter being now withdrawn, and the finger or a pair of forceps introduced into the bladder, the calculus may be grasped and extracted. There are some instances in which as many as 20 or 30 small calculi have been taken from the bladder of a dog. Twice I have seen calculi absolutely crushed in the bladder of a dog; and Mr. Blaine says that he found no fewer than 40 or 50 in the bladder of a Newfoundland dog. One of them had passed out into the urethra, and had so blocked up the passage that the flow of urine was prevented, and the animal died of mortification. With much pleasure I refer to the details of Mr. Blaine with regard to the management of 'vesical calculi'. "When a small calculus," says he, "obstructs the urethra, and can be felt, it may be attempted to be forced forward through the urethra to the point of the penis, whence it may be extracted by a pair of forceps. If it cannot be so moved, it may be cut down upon and removed with safety; but when one or more stones are within the bladder, we must attempt lithotomy, after having fully satisfied ourselves of their existence there by the introduction of the sound; to do which it must be remembered that the urethra of the dog in passing the bladder proceeds nearly in a direct line backwards, and then, making an acute angle, it passes again forwards to the bladder. It must be therefore evident, that when it becomes necessary to introduce a catheter, sound, or bougie, it must first be passed up the penis to the extremity of this angle; the point of the instrument must then be cut down upon, and from this opening the instrument may be readily passed forward into the bladder. The examination made, and a stone detected, it may, if a very small one, be attempted to be pushed forward by means of a finger passed up the anus into the urethra; but, as this could be practicable only where the dog happened to be a large one, it is most probable that nothing short of the operation of lithotomy would succeed. To this end, the sound being introduced, pass a very small gorget, or otherwise a bistoury, along its groove into the bladder, to effect an opening sufficient to admit of the introduction of a fine pair of forceps, by which the stone may be laid up and extracted." 'Blaine's Canine Pathology', p. 180. INFLAMMATION OF THE BLADDER