URINARY APPARATUS. 177 



Accordingly we consider the following points and in the 1 

 order given: 



I. Manner of Avoiding the Urine. 

 II. Examination of the Urine. 



A. Macroscopical examination. 



B. Chemical examination. 



C. Microscopical examination. 



III. Examination of the Urinary Organs. 



I. Manner of Voiding the Urine. 



In our domestic animals urinating is a reflex act inaugurated 

 by the stimulus of the urine on the mucous membrane of the dis- 

 tended bladder. As long as the distention of the bladder is below a 

 certain point the reflex action of the sphincter vesicae which is 

 also inaugurated by the pressure of the urine, supersedes that of 

 the muscular coat, hence the one gives way to, or takes the place 

 of, the other as occasion demands. 



In adult male dogs only do we observe frequent and 

 voluntary urination. For this act they prefer places used for the 

 same purpose by other dogs. Their favorite places are trees, the 

 corners of houses, etc. 



When urine is voided the bladder contracts and this is aided 

 by the abdominal muscles. Every species of animal manifests 

 peculiarities of its own in this act, but it is a rule that all animals 

 stand while urinating. 



Horses (both sexes) urinate only while resting and cease feed- 

 ing for the time; not infrequently they emit loud groans. 



Cows urinate similarly to mares, male cattle on the other 

 hand urinate not only while feeding but also while walking; in 

 fact, in these animals 'the act seems almost to be a passive one. 



Old dogs and pigs (male) void the urine in an interrupted 

 jerky stream. 



a. The frequency of urination depends on the amount of 

 water imbibed, the amount of water lost by respiration, perspira- 

 tion, and per intest'nal tract; accordingly it varies very consider- 

 ably. Healthy horses ordinarily urinate 5-6 times a day. 



1. Abnormally frequent urination in usual volumes is 

 a result of increased secretion (polyuria) 



2. Diminished urination is not easily recognized in ani- 

 mals. In doubtful cases a clean cloth bandage may be tied 

 over the prepuce (in the ox) to determine whether the act 

 takes place at all. Urination is diminished or suppressed: 



