130 EESPIRATION. 



which exists between a part locally affected and the system at 

 large. An injury inflicted upon the foot wiU not unfrequently 

 give rise to violent commotion of the respiratory organs ; so 

 that rapid breathing, when the animal stands at rest, accom- 

 panied as it generally is with other symptoms indicative of 

 violent disturbance vrithin the system, is not at all times to be 

 regarded as noting the existence of acute disease vpithin the 

 lungs. As a general rule, however, when the lungs are directly 

 affected, there are certain sounds associated with the breathing 

 of the patient .which betoken whether the disturbance be 

 primary to these organs or not. The reader will find the 

 nature and the peculiarties of these sounds treated upon in 

 the section devoted to those diseases incidental to the respira- 

 tory organs. A respiration is the result of a double act ; that 

 is, it consists of one inspiration and one expiration. The 

 average number of respirations of a healthy horse per minute 

 is about twelve. As a general rule, the pulse of the animal 

 wiO. beat three times during the production of one respiration. 

 The average now given, and the relation of the respiratory act 

 to the pulse, must be understood as strictly referring to the 

 animal when in the stable and free from all excitement. 



When the lungs are diseased, the respirations will at times 

 reach from fifty to sixty per minute, or even more, — in short, a 

 very exact limit cannot be stated ; they should be always noted, 

 however, with care. To an experienced observer, the manner 

 in which the act of breathing is performed is significant in the 

 extreme. In pleurodynia and pleurisy the act is limited and 

 constrained, attended vsith a peculiar tremor of the muscles of 

 the sides, a pinched appearance of the alse of the nostrils, a 

 slight arching of the back, and if the sides are pinched or 

 pressed upon, a peculiar grunt is emitted. In tetanus the 

 respiratory act is also limited, and in many respects closely 



