4 i8 VETERINARY LECTURES 



bladder, or in the urethra, causing retention of the urine, and, if 

 not removed, may probably cause rupture of the bladder. The 

 horse and dog are most often affected with these troublesome con- 

 cretions. Symptoms. — These are somewhat like those of retention 

 of the urine. In some cases the animal may be urinating fully and 

 freely, when all at once the flow is arrested, the horse making 

 frequent attempts to stale, groaning and straining, but only 

 managing to pass a few drops. On examination by the rectum, 

 calculi are at times found crowding around, especially in the neck of 

 the bladder ; these, by manipulation with the fingers in the rectum, 

 may be displaced, and the animal relieved. Sometimes a calculus 

 gets into the urethra, where it sticks a few inches below the anus ; 

 it can be seen and felt at the point of stoppage, the parts above 

 bulging out, while the urine trickles down the thighs. With a little 

 labour the stone may be worked back into the bladder, the action 

 being assisted by gently passing up the catheter, or it may get so 

 far down near the end of the penis that it can be cut down upon and 

 removed. When calculi in the bladder of the horse give rise to pain 

 and inconvenience, they have to be extracted by an operation called 

 lithotomy. In this operation the animal is cast and tied much 

 in the same way as for castration ; the passage is cut into below the 

 anus, and with suitable instruments the stones are removed, either 

 whole or crushed. 



726. Bulls, Rams, and Wethers, when too largely fed on 

 mangold-wurzels, or turnips grown with superphosphate alone, 

 suffer from accumulations of white crystals — the amnionic magnesium 

 phosphates— in the bladder and urethral passage. When a bull is 

 fed to excess on mangolds, it invariably proves unfruitful. I think 

 this is due to crystals, which have lodged in the barrel of the penis, 

 being transmitted along with the semen at the time of service, 

 interfering with fruitful conception. I have frequently gathered 

 these concretions from the hairs surrounding the sheath of animals 

 which have been feed on the above-named foods. In the ram the 

 passage and vermiform process, or worm, on the end of the penis is 

 often entirely blocked with these concretions. When thus affected 



