156 EXAMINATION 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 bronchit 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 eommon seats of in- 
flammation (bronchitis), which leads sometimes to the 
following sequences :— 
x. Thickened mucous membrane. 
2. Stricture of the tubes affected. 
3. Dilated air cells. 
4. Thinning of their walls, and obliteration of their 
capillaries. 
