84 THE FARM DOCTOR. 



only made in drawing air in. But any obstruction in the large 

 air tubes will give rise to roaring, heard most commonly in both 

 inspiration and expiration. Thus palsy of the nostrils, fracture, 

 and depression of the bones of the nose, tumours in the nose, 

 throat, windpipe, or bronchi, false membranes extending across 

 the air passages, dropsical swelling about the throat, and in 

 stallions undue accumulations of fat, may give rise to it. In the 

 typical form, with palsy of the laryngeal muscles, the animal 

 grunts (groans) when led up to a wall and a feint is made to 

 strike him on the ribs. If galloped up a steep hill or over a 

 newly-ploughed field, or even for some distance on level ground, 

 the roaring is strikingly brought out. The same holds good U 

 made to draw a heavy load or one with the wheels dragged. 



Treatment. — In incipient cases with simple thickening of the 

 mucous membrane, benefit may arise from swabbing out the 

 larynx with nitrate of silver solution, as recommended for croup, 

 or firing the skin over the throat with a red-hot iron. But if 

 the muscles are wasted and fatty these means will be fruitless, 

 and we must look to mechanical or surgical measures for help. 

 Pads attached to the nose-band of the bridh, and so arranged 

 that they will lie on the false nostrils and check somewhat the 

 ingress of air, will enable many roarers to do moderate work 

 with comparative comfort In the worst cases, in which the 

 animal is rendered useless, tracheotomy may be performed, and 

 Jhe animal made to breathe through a tube inserted in the 

 middle of the neck. Or finally, the larynx may be laid open 

 with the knife, and the flap of gristle (arytenoid), which is drawn 

 in, valve-like, over the opening by the current of air, cut off. 



Some cases of roaring due to feeding on vetches {Lathyrus 

 Sativa or Cicero) may be cm'ed by changing the feed, and giving 

 some doses of nux vomica. Others due to dropsical effusions 

 appear intermittently, and may be benefited by tonics and iodide 

 of potassium, with hard, dry feeding and exercise. Tumours and 

 other mechpnical obstnictions must be removed with the knife. 



