The genesis of gall stones in the dog

Abstract

In dogs permanently intubated for the collection of bile, gall stones not infrequently develop despite the absence of infection, stasis and gall bladder activity. The character of the stones has already been discussed. 1 They are always discrete to begin with, scattered upon the glass and rubber wall of the collecting tube. What determines this punctate localization? In certain instances, of almost pure calcium carbonate concretions, the answer is plain. These form in the midst of organic debris, not infrequently around bits of talc from the tube surface. In other cases minute, rounded, pigmented particles from the bile lodge upon the tube wall, and stone formation takes place upon these as nuclei. To trace the source of such particles and their significance we have made day to day studies of the sediment from sterile 24 hour specimens of bile centrifuged on removal from collecting balloons devoid of air. Also we have followed the early stages of calculus formation in the collecting tubes of the same animals.

The bile was found to yield formed elements identical with those later recovered from the tube system and from the interior of stones forming upon the walls of the latter. The nature and the amount of the sediment vary with the condition of the animal. For a day after the operation whereby intubation is effected it may consist merely of mucus, which later is seldom met with. Usually one obtains from the specimen of the second 24 hours after operation and perhaps more abundantly from that of the third, a slight brown deposit, made up, as the microscope shows, of minute, highly ref ractile, translucent, yellow-brown granules. The shape of these tends to be spherical, but is rendered various by the partial merging of the spheres.