DISEASES OF THE EESPIEATOEY OEGANS. 1(^' ^ 



In chrojiie roaring there is no evidence of any disease of the larynx 

 other than the wasted condition of the muscles in question. The 

 disease of the nerve is generally far from the larynx. Disease of 

 parts contiguous to the nerve along any part of its course may inter- 

 fere with its proper function. Enlargement of lymphatic glands 

 within the chest through which the nerve passes on its way back 

 to the larynx is the most frequent interruption of nervous supply, 

 and consequently roaring. When roaring becomes confirmed, medical 

 treatment is entirely useless, as_it is impossible to restore the wasted 

 muscle and at the same time remove the cause of the interruption 

 of the nervous supply. Before roaring becomes permanent the con- 

 dition may be benefited- by a course of iodid of potassium, if caused 

 by disease of the lymphatic glands. Electricity has been used with 

 indifferent success. Blistering or firing over the larynx is, of course, 

 not worthy of trial if the disease is due to interference of the nerve 

 supply. The administration of strychnia (nux vomica) on the 

 ground that it is a nerve tonic with the view of stimulating the af- 

 jfected muscles is treating only the result of the disease without con- 

 sidering the cause, and is therefore useless. The operation of extir- 

 pating the collapsed cartilage and vocal cord is believed to be the 

 only relief, and, as this operation is critical and can be performed 

 only by the skillful veterinarian, it will not be described here. 



From the foregoing description of the disease it will be seen that 

 the name " roaring," by which the disease is generally known, is only 

 a symptom and not the disease. Chronic roaring is also in many 

 cases accompanied with a cough. The best way to test whether a 

 horse is a "roarer" is either to make him pull a load rapidly up a 

 hill or over a sandy road or soft ground ; or, if he is a saddle horse, 

 gallop him up a hill or over soft ground. The object is to make him 

 exert himself. Some horses require a great deal more exertion than 

 others before the characteristic sound is emitted. The greater the 

 distance he is forced, the more he will appear exhausted if he is a 

 roarer; in bad cases the animal becomes utterly exhausted, the 

 breathing is rapid and difficult, the nostrils dilate to the fullest ex- 

 tent, and the animal appears as if suffocation was imminent. 



An animal that is a roarer should not be used for breeding pur- 

 poses. The taint is transmissible in many instances. 



Grunting. — ^A common test used by veterinarians when examining 

 " the wind " of a horse is to see if he is a " grunter." This is a sound 

 emitted during expiration when the animal is suddenly moved, or 

 startled, or struck at. If he grunts he is further tested for roaring. 

 Grunters are not always roarers, but, as it is a common thing for a 

 roarer to grunt, such an animal must be looked upon with suspicion 

 until he is thoroughly tried by pulling a load or galloped up a hill. 

 The test should be a severe one. Horses suffering with pleurisy, 



