50 Veteriyiary Medicine. 



Causes. As in stomatitis the starting point of pliaryngitis is 

 usuall}^ in a local injury or a systemic condition which lowers the 

 vitalit}^ of the pharyngeal mucous membrane. It may come in 

 all animals from the hot air of burning buildings, from acrid 

 gases inhaled, food, drink or medicines given at too high a tem- 

 perature, from caustic alkalies, acids or salts, from physiological 

 irritants like croton, euphorbium, cantharides, from barley and 

 other spikes entangled in the follicles, from drinking freely of 

 iced water. In solipedes there are the injuries caused by giving 

 boluses on pointed sticks, and the wounds caused b^^ tooth files 

 in careless hands, and b}' coarse fibrous fodder, which has been 

 swallowed without due mastication. In cattle injury comes from 

 foreign bodies impacted, from the rough use of probang, rope or 

 whip and even of the hands in relieving choking. Swine have 

 the part scratched and injured by rough or pointed objects which 

 they bolt carelessl}^ with the food. Dogs and especially puppies 

 are often hurt by solid and irritant bodies that they play with, 

 and swallow accidentally or wantonly. They also suffer at times 

 from the pressure of a tight or badly adjusted collar. 



Tlie sy.stem is debilitated and rendered more susceptible by 

 chills consequent on exposure to cold blasts, or draughts, or rain 

 or snow, when heated and exhausted, by cold damp beds, b}' pre- 

 existing disease, by underfeeding and by overwork. In the 

 larger animals this may come from the excessive ingestion of 

 iced water, while in dogs the plunging in rivers, ponds or lakes 

 ma)^ chill. 



The weakness of early age and old age have a perceptible pre- 

 disposing influence especially in solipeds and carnivora. 



Finally as in other catarrhal inflammations the local action of 

 disease germs on the mucous membrane must ever be borne in 

 mind. These ma}' be the germs of specific diseases localized in 

 the pharynx ; — in Solipeds the streptococcus of strangles, the 

 bacillus of glanders, the diplococcus (streptococcus) of conta- 

 gious pneumonia, the germ of influenza, and actinomyces ; — in 

 Cattle the bacillus tuberculosis, the bacillus of anthrax, actino- 

 mj'ces, the germs of aphthous fever and of pseudomembranous 

 angina ; in dogs canine madness and distemper ; — in birds the 

 bacillus of pseudomembranous pharyngitis. 



In addition to such specific germs the micrococci, streptococci 



