RESPIRATORY APPARATUS. 91 



VI. The cough. 



VII. The voice. 



VIII. The laryngeal region. 



IX. T h e t r a c h e a . 



X. The percussion of the thorax. 



XL The auscultation of the thorax. 



1. The Respiratory Movements. [Respirations]. 



The respirations should be examined in regard to fre- 

 quency, manner in which produced, and any special 

 sounds originating during the act of breathing. These 

 three factors help to determine whether dyspnea be 

 present or not. 



Frequency of respirations. To determine the number of res- 

 piratory movements per minute each rise or fall of the flanks 

 or ribs is counted. Observing the play of the nostrils is not as 

 certain a method, as these organs can be voluntarily moved by 

 the animal. In winter the breath can be seen appearing as steam 

 at each expiration. The respirations should be counted for at 

 least thirty seconds; in restless animals the veterinarian should 

 stand quietly near, count several times and take the average ob- 

 tained as the respiratory frequency. 



The smaller the animal the greater the number of respira- 

 tions. In one and the same animal the number of respirations 

 per minute will vary within physiological limits. 



Just after partaking of food, or when the abdomen is very 

 full, and especially after exercise, an acceleration of respira- 

 tions is a normal consequence. High atmospheric tempera- 

 tures, restlessness and anxiety, also make the breathing more 

 hurried. In adult animals standing at perfect rest the follow- 

 ing number of respiratory movements per minute may be 

 taken as the average normal : 



Horse 8-16 



Ox 10-30 



Sheep and goat 12-30 



Swine 10-20 



Dogs 10-30 



Cats 20-30 



Fowls 40-50 



