84 



more commonly thoy are large masses and lodged in the pelvis. The 

 larger calculi, sometimes weighing 12 to 24 ounces, are molded in the 

 pelvis of the kidney into a oylindroid mass, with irregular rounded 

 swellings at intervals. Some have a deep brown, rough, crystalline 

 surface of oxalate of lime, while others have a smooth, pearly white 

 asiDect from carbonate of lime. A smaller calculus, which has been 

 called coralline, is also cylindroid, with a number of brown, rough, 

 crj^stalline oxalate of lime branches and whitish depressions of carbo- 

 nate. These vary in size from 15 grains to nearly 2 ounces. Less 

 frequently are found masses of very hard, brownish white, rounded, 

 pea-like calculi. These are smoother, but on the surface crystals of 

 oxalate of lime may be detected with a lens. Some renal calculi are 

 formed of more distinct layers, more loosely adherent to each other, 

 and contain an excess of "mucus but no oxalate of lime. Finally a 

 loose aggregation of small masses, forming a very friable calculus, is 

 found of all sizes within i\ie limits of the pelvis of the kidne}'. These, 

 too, are in the main carbonate of lime (84 to 88 per cent), and without 

 oxalate. 



Symptoms of renal calculi are violent colicky pains appearing sud- 

 denly, very often in connection with exhausting work or the drawing 

 of speciall}^ heavy loads, and in certain cases disappearing with equal 

 suddenness. The nature of the colic becomes more manifest if it is 

 associated with stiffness of the back and hind limbs, frequent passage 

 of urine, and above all the passage of gravel Avith the urine, especially 

 at the time of the access of relief. The passage of blood and i)us in 

 the urine is equally significant. If the irritation of the kidney goes 

 on to active inflammation then the symptoms of nei^hritis are added. 



Uretral Calculi. — These are so called because they are found in the 

 passage leading from the kidney to the bladder. They are simply 

 small renal calculi which have escaped from the i^elvis of the kidney 

 and have become arrested in the ureter. They give rise to symptoms 

 almost identical with those of renal calculi, with this difference, that 

 the colicky pains, caused by the obstruction of the ureter by the 

 impacted calculus, are more violent, and if the calculus passes on 

 into the bladder the relief is instantaneous and complet-e. If the 

 ureter is completely blocked for a length of time the retained urine 

 may give rise to destructive inflammation in the kidney, which may 

 end in the entire absorption of that organ, leaving only a fibrous cap- 

 sule containing an urinous fluid. If both the ureters are similarly 

 blocked the animal will die of ura^mic poisoning. 



Treatment of Renal and Uretral Calculi. — This is unsatisfactory, as 

 it is only the small calculi that can pass through the ureters and 

 escape into the bladder. This may be favored by agents which will 

 relax the walls of the ureters by counteracting their spasm and even 

 lessening their tone, and by a liberal use of water and waterj^ fluids 

 to increase the urine and the pressure upon the calculus from behind. 



