DISEASES OF THE RESPIRATORY TRACT 4I 



disease can be given wallowing in cold springs and 

 creeks when the body is in an overheated condition, 

 being deprived of water and slop during a warm, 

 dry spell, close, filthy pens, debility, septic germs 

 entering the mouth and throat along with the food, 

 and the germs of hog cholera and swine plague. 

 Filthy pens often contribute to the infection of the 

 throat with septic germs, and the formation of ab- 

 cesses and ulcers on the lining membrane. 



Symptoms. — There is more or less fever, the eyes 

 are red and watery, and the animal is dull and lies 

 around the pen most of the time. The appetite is 

 I poor, and because of the pain and difficulty in 

 swallowing, the hog may refuse food. The pain in 

 the troat is sometimes severe, and causes the ani- 

 mal to move about in a restless manner. 



The character of the cough depends on the parts 

 inflamed. When the larynx is involved, the cough 

 is usually hoarse and the breathing noisy and la- 

 bored, as the glottis is more or less closed by the 

 inflammation. At other times it is dry, and when 

 the hog moves about, or the parts are irritated by 

 dust, cold air, etc., a coughing spell usually comes 

 on. The throat may appear swollen. 



In germ infection from the feed and filth, and in 

 infectuous diseases (swine plague, hog cholera, etc.), 

 false membranes may form, or the mucous mem- 

 brane lining the part becomes gangrenous and ul- 

 cerated. In such cases the disease usually devel- 

 ops rapidly, and the air passages become closed 

 within a few hours by the swelling and membranes. 



