THE RESPIRATORY APPARATUS . 303 



CHAPTER v.— DISEASES OF THE RESPIRATORY 

 APPARATUS. 



The calibre of tLe air-passages of tlie ox is not so great 

 as that of the horse; the lungs are practically smaller, 

 and M. Colin has shown us that an ox breathes only about 

 82 per cent, of the amount of air required by a horse, 

 throwing off a proportionately small amount of carbonic 

 anhydride. This would lead us to anticipate that the 

 ordinary diseases of the respiratory organs of the ox are 

 less numerous and important than those of the horse. It 

 adapts the animal less for rapid and prolonged locomotion, 

 and is in accordance with the conditious of other parts of 

 the system ; thus, the large gastric mass of the ox prevents 

 rapid exertion after a meal, and the full conditions of these 

 organs remains for a long time. During this the action 

 of the diaphragm must be, to a certain extent, impeded as 

 far as its respiratory functions are concerned ; it facilitates 

 regurgitation constantly during rumination. Again, its 

 position is more upright. The conformation of the 

 skeleton of the ox gives us information that he is less 

 adapted for respiratory emergencies than the horse. 

 Ordinary respirations of the ox are frequent and not 

 deep, 15 to 18 in the adult, 18 to 20 in the young animal ; 

 they are liable to considerable increase in number even 

 during health. Similarly the healthy cough of the ox is 

 rather short and weak. The horse suffers so frequently from 

 disorders of the respiratory organs because he is pushed 

 to extremes of exertion, is pampered in hot, close, and 

 improperly ventilated stables, and is subjected to sudden 

 changes of temperature of the surrounding medium, and also 

 exposure to draughts, and under certain circumstances to 

 extremes of weather. With the skin acting profusely he 



