114 The Diseases of Animals 



the lungs, with a partial closure of the glottis. It 

 is an endeavor to remove some irritating substance 

 from the lungs or throat. There are two varieties of 

 cough commonly recognized by veterinarians. The 

 "moist" cough, in which mucus is expelled, accompanies 

 an excessive secretion and collection of fluids in the 

 air-passages. The "dry" cough is of a hacking nature 

 and indicates irritation of the throat or lungs. 



THE MUCOUS MEMBRANE 



The mucous membrane is the soft, smooth, pink 

 lining of all the natural openings of the body. It 

 lines throughout its length the alimentary canal, and 

 all other organs to which the external air may be 

 admitted. If any mucous surface is congested and 

 red, it shows a general irritated condition of this 

 tissue. Such a condition is observed in the disease 

 commonly called "pink-eye." If the mucous mem- 

 branes are abnormally pale, it indicates a debilitated 

 or anaemic condition of the body. A sudden and 

 marked pallor of the mucous membranes accompanies 

 an excessive loss of blood. If it is blue or slate - 

 colored, a lack of oxygen in the blood is indicated. 

 A yellow tint in the mucous membrane shows that the 

 liver is deranged. 



EXCRETIONS 



The excretions of the body, the faBces (dung), 

 urine and perspiration, vary, in diseased animals, not 

 only in quantity and appearance, but often in com- 



