439 



CHAPTER XXI. 



Diseases op the Urinaby Organs. 



general remarks retention op urine bloodt urine ^inplam- 



mation op the bladder albuminous urine ^inplammation of 



q^hb kidneys stone in the bladder. 



General Remarks. 



The exact nature of diseases of the uriaary organs is often difficult 

 to determine ; for unusual conditions of the urine and symptoms 

 of disease of these organs may be present, without anything being 

 wrong with theon, as seen in hsemoglobinuria, diabetes, and con- 

 stipation. To correctly inrestigate these diseases, one should be 

 able to analyse urine, to do which, a knowledge of chemistiy and 

 microscopy is necessary. I shaU therefore only briefly refer to 

 these diseases, which, happily, are rare in the horse, except in 

 the case of retention of urine as an accompaniment of colic. 



The kidneys (Fig. 141, p. 349), two in number, are the glands 

 which form urine from the blood. As the urine is secreted, it is 

 carried away from the kidneys into the bladder by the ureters, 

 which are narrow tubes, and is finally got rid of by means of t)ie 

 urethra, which is a comparatively large tube that connects the 

 bladder with the penis of the horse and with the vagina of the 

 mare ; expulsion being effected by the contraction of the muscles 

 which surround the bladder. 



Retention of Urine. 



This is a symptom of disease rather than a disease in itself. It 

 is generally caused by spasm of the neck, of the bladder ; paralysis 

 of the bladder ; the accumulation of hardened soapy matter in the 

 sheath, owing to neglect of cleanliness ; by the horse having been 

 kept too long from staling ; by impaction of the rectum with hard 

 dung ; and by chill. It may also be due to the presence of stone 



