1 56 EX A MINA TION OF HORSES 



of the mucous membrane, and not unfrequently by 

 ulceration, either of which may give rise to chronic 

 cough that may end in "broken wind." When these 

 conditions are present, if you pinch the larynx at its 

 lower part, and "cough" the horse, he will not just give 

 one or two hearty good coughs, as he would in health, 

 but he will keep on coughing ; and the cough is short 

 and wanting in strength, and will be sepulchral or hol- 

 low, and accompanied by a distressing noise, if there is 

 " broken wind." A chronic thickening of the lining of 

 the larynx and vocal cords gives rise to what is termed 

 thick wind. 



All these affections, and indeed nearly every affection 

 of the larynx, is almost of necessity of grave import, 

 and amounts to unsoundness. 



The trachea and bronchii are always patent, especially 

 the former, which cannot very well be the seat of such 

 constriction as would lead to unsoundness. Sometimes, 

 however, when it has been the subject of tracheotomy 

 badly performed, and has worn the tube too long, a 

 thickening, giving rise to a stricture, has been known 

 to result. The bronchii are the common seats of in- 

 flammation (bronchitis), whkh leads sometimes to the 

 following sequences : — 



1. Thickened mucous membrane. 



2. Stricture of the tubes affected. 



3. Dilated air cells. 



4. Thinning of their walls, and obliteration of their 

 capillaries. 



