Diseases of Metabolism. 



1. Obesity. Obesitas. 



Fettsucht. 



By obesity is understood an excessive deposit of fat which 

 interferes in some way or other witli the abihty of the animals 

 to work. If tlie increase of the fat deposit occurs while nutri- 

 tion and muscular activity are normal, it is called obesity in 

 a limited sense of the word, in contrast to the alimentary obesity 

 (fattening), which is the result of generous feeding or of in- 

 activity. 



Etiology. The cause of alimentary obesity lies in a dis- 

 proportion between the intake and the utilization of nutritive 

 units. This condition very frequently prevails if the animals 

 receive more food than they need in order to maintain their 

 bodily functions. It also occurs frequently enough that the 

 intake of caloric units does not exceed the average amount, but 

 that through insufficient activity the muscles of the body use 

 up too small an amount of energy-units. Finally, both factors 

 frequently combine in producing obesity. 



A generous deposit of fat is promoted above all by the 

 fattening of animals intended for food, but although strictly 

 speaking a pathological condition, this does not usually form 

 an object for therapeutic measures. Obesity is further fre- 

 quent in breeding animals, especially in the males, which are, 

 as a rule, not only fed generously, but are moreover spared 

 all work, and are even not rarely prevented from taking the 

 most necessary exercise. The same is true of pet and house 

 dogs. In general, however, favoring factors are of essential 

 importance. Above all a vigorous appetite comes into consider- 

 ation, which apparently varies individually within wide limits. 

 Then the nature of the food is important, food-stuffs which are 

 rich in fat and carbohydrates producing a considerable fat de- 

 posit. On the other hand the deposit of fat is promoted by 

 all conditions which persistently diminish muscular activity. 

 In this respect the phlegmatic temperament which may be in- 



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