CHAPTER LXVIII. 



SPOEADIC DISEASED— continued. 



LOCAL DIQ'EAQES— continued. 



(R.) DISEASES OF THE KIDNEYS. 



Owing to the fact that the lower animals are free from Inental 

 emotions, the cares and troubles of the world, and that they 

 do not indulge in alcoholic drinks, the kidneys are in a great 

 measure exempt from those diseases wliich so often destroy 

 human life. 



Diseases, however, do occur with which the veterinarian has 

 to cope. Physiologically, the kidneys excrete from the body 

 those materials resulting from metamorphosis of tissue which 

 would, if retained, act injuriously upon the system generally ; 

 and the secreted material — the urine — differing as it does in 

 various animals, contains certain constituents, some of them 

 identical, some dissimilar. The presence of these constituents 

 in normal or abnormal quantities, or their absence, indicate to 

 the investigator various morbid conditions of the kidneys, as well 

 as many changes which occur in tlie body during disease. The 

 urine is naturally alkaline in the herbivora, and acid in flesh- 

 eating animals. It consists of a large amount of water ; a nitro- 

 genous substance called urea; an acid — hippuric in that of 

 herbivora, and uric in the carnivora; colouring matter called 

 uro-hsematin ; inorganic salts ; organic substances of an ill-defined 

 nature called extractive matters. 



The density of healthy urine of the horse, appears to range 

 from 1030 to 1050 ; that of the ox has a specific gravity ranging 

 from 1032 to 1040; that of pigs 1010 to 1012; and of the goat 

 1008 or 1009. — (Von Bibra.) The amount of water in the 

 urine varies much, according to the quantities of fluids that have 



