310 STABLE MANUAL AND HORSE DOCTOR 



addition to the practice is a blister or mustard poultice to 

 the throat, with a fever ball, containing half a drachm of 

 tartar emetic and a drachm of nitre, night and morning. 

 Purgatives to be omitted, the food scalded, and the water 

 chilled. 



CHRONIC DISEASES OF THE AIR-PASSAGES. 



ROARING — CHRONIC COUGH — THICK WIND — BROKEN WIND — 



STRANGLES. 



The artificial life of the domesticated horse occasions 

 numerous diseases and changes of structure in his respira- 

 tory organs. Not only do the great lobes of the lungs 

 suffer, but the passages to them are altered in dimension, 

 and more or less obstructed, so that the sound produced 

 by the passage of air is modulated, and *' wheezing," 

 " whistling," " roaring," etc., become familiar terms among 

 horsemen. Thus, a horse " wheezes " when any obstruction 

 exists in the nostrils; "whistles" when the obstruction is 

 situated further back and near the opening to the larynx ; 

 and " roars " when the larynx is malformed, or the 

 hindrance to the passage of air lies within the windpipe. 



Roaring. — The causes of roaring are of two classes, acute 

 and chronic. The acute are from obstructions accidentally 

 formed, as cicatrices from wounds or injury, foreign sub- 

 stances lodged in the windpipe, extravasation of fluid or 

 coagulable lymph, which, once organised, forms a permanent 

 obstruction ; when this extends up to the glottis it produces 

 whistling. Whoever has handled the throats of many old 

 horses must have observed a hardened state of the larynx, 

 which almost resisted all attempts to what is termed 

 "cough them." This ossification is not an uncommon 

 cause ; and a similar state in the cartilages of the trachea 

 is productive of it also. A cause, also, of roaring is a band 

 of lymph stretched across the tracheal tube ; at others, an 

 internal ring of the same matter simply diminishes its 

 diameter. The obstruction is sometimes so considerable as 

 to excite the sound upon the slightest exertion ; in general 

 cases, however, roaring is only exerted when forcible in- 

 spirations and expirations are made. Mechanical obstruc- 

 tions to free respiration may eventually be productive of 

 roaring. The custom of tightly reining in our carriage- 

 horses, especially such as run in pairs, or double harness, 



