DISEASES OP THE DIGESTIVE SYSTEM. 175 



What is the pathology? 



The mucous membrane becomes tumefied, reddened, and infil- 

 trated; an increased amount of secretion takes place, which becomes 

 purulent and glairy, holding white or yellowish-white clots in sus- 

 pension. 



The watery parts may become absorbed or evaporated, the re- 

 mainder undergoing degeneration and becoming absorbed, or may 

 dry up and form calculi, which are variable in size, from a pinhead 

 to a chestnut. 



Gas is sometimes present in these pouches. 



The neighboring lymphatic glands are hard and somewhat en- 

 larged. 



Give the causation and symptoms. 



The inflammation is generally secondary, often following or 

 associated with parotitis, pharyngitis, or colt distemper. 



The Eustachian tube may become closed, preventing the escape 

 of pus, which accumulates (generally on one side, becoming much 

 swollen, causing difficult breathing (dyspnoea) and even roaring, 

 and also interfering with deglutition by pressure on the larynx 

 and pharynx). 



It may become so distended as to burst or cause death by suffo- 

 cation or gangrene of the lungs. 



In other cases the pus escapes from the nostrils — either one or 

 both; if unilateral, the veterinarian looks for glanders. 



The discharge is intermittent in character, and depends on the 

 position of the head, it being increased when the head is lowered. 

 Mastication and deglutition often increase the flow, as will exercise. 



The intermaxillary glands are swollen in most cases, and are 

 usually soft to the feel and movable under the skin. 



The discharge varies in quality, generally being of a thick and 

 creamy consistency and odorless. It comes out of the most depend- 

 ing part of the nostril, and does not form crusts, and is not very 

 sticky. 



If we suspect this condition, we look at the parotid region, and 

 there we find a swelling which, if pressed on, is painful and often 

 causes the pus to flow out. 



How is the diagnosis made ? 



By a thick, odorless, creamy, and clotty discharge from one or 

 both nostrils, being intermittent, and increased by mastication, deg- 



