CHAPTER IV. 



DISEASES OF THE LUNGS. 



Examination. — The following things are essential for a 

 complete and thorough examination: 



1 . The number and character of the respiratory movements. 



2. The size, shape and sensitiveness of the thorax. 



3. Auscultation. 



4. Percussion. 



1. Respiration.— In small animals the number of respira- 

 tory movements normally varies greatly. The average 

 number while at rest is 12-24. This is easily and quickly 

 increased by excitement and exercise until they may reach 

 60-90 per minute. During warm weather even while at rest 

 the respirations are greatly accelerated, owing to the skin 

 glands not being active enough to assist in the respiratory 

 function. In order to overcome this physiological condi- 

 tion the animal breathes forcibly through the mouth, and the 

 frequency of respirations is increased. Respiratory move- 

 ments are also increased in the following diseased conditions: 

 Catarrhal pneumonia, foreign body pneumonia, chronic 

 interstitial pneumonia, usually when the temperature is 

 elevated, in laryngitis, acute and chronic bronchitis, hydro- 

 thorax, pleurodynia, ascites, peritonitis, valvular insuffi- 

 ciencies, eclampsia and during the early stages of some poi- 

 sonings. A lessening in the number of respirations is found 

 in narcotic poisoning, diseases of the brain and its membranes 

 and in the later stages of infectious diseases, septicemia and 

 pyemia. 



2. The Thorax.— In shape both sides of the chest wall 

 should be symmetrical. Depression on one side indicates 

 fractured ribs or pleurodynia. Distention of the thorax is 

 seen in hydrothorax, and in fluid accumulations (ascites), 

 tumors or when the stomach is distended, causing pressure 

 against the diaphragm. 



3. Auscultation is practised by using the phonendoscope 

 or by covering the thoracic wall with a piece of cloth against 



