68 Roaring in Horses. 



be ridden by the expert, who leans forward, the easier to 

 hear the respiration ; but it is perhaps better if he stand at 

 a particular point and the horse be made to gallop past, 

 close to him, with its head as free as is compatible with 

 control. Some authorities recommend keeping the animal's 

 nose well in towards the chest when galloping, others curve 

 the neck to the right side, while others again, gallop the 

 horse in a circle. The latter demands care, as horses some- 

 times make a noise — irregular, it is true — when galloped in 

 a small circle, which yet respire perfectly free when going 

 in a straight line. 



For draught-horses, which cannot be so conveniently 

 galloped, putting them to draw a load in heavy ground or 

 up an incline is the most reliable test. 



Exciting or frightening is by no means a sure test, 

 though often resorted to when the preceding ordeals cannot 

 be imposed. Some horses which are decided Roarers when 

 galloped or otherwise exerted, will not make a noise when 

 threatened by whip or cane. Neither is " coughing " a 

 reliable or possible test in all cases. When the disease is 

 not very advanced, the cough is but little, if any, different 

 from that of health. And when other morbid conditions of 

 the air-passages are present, as chronic laryngitis or bron- 

 chitis, or emphysema of the lungs, these will produce their 

 own particular effect on the cough, and so modify it. Even 

 perfectly healthy horses, when the larynx is severely com- 

 pressed and its dilator muscles temporarily paralyzed 

 thereby, will sometimes emit a cough not unlike that noticed 

 in Roarers. In other cases, confirmed Roarers cannot be 

 made to cough, owing to loss of sensibility in the mucous 

 membrane of the air-tube, from wasting of the nerve sup- 

 plying it, or changes due to chronic inflammation. 



Direct manual examination of the larynx itself is valu- 

 able in ascertaining the condition of that organ, especially 

 if the muscular wasting on the left side is at all considerable; 

 and, with practice, the expert has generally little difficulty 



