148 HORSE, SWINE AND POULTRY. DISEASES 



In chronic 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 located far from the larynx. 

 Disease of parts contiguous to the nerve along any part of its course 

 may interfere with its proper function. Enlargement of lymphatic 



lands within the chest through -which the nerve passes on its way 

 ack to the larynx is the most frequent interruption of nervous sup- 

 ply, 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 per- 

 manent the condition may be benefited by a course of iodide of 

 potassium, if caused by disease of the lymphatic glands. Electric- 

 ity 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 affected muscles is treating only the result of the 

 disease without considering the cause, and is therefore useless. The 

 operation of extirpating the collapsed cartilage and vocal cord is 

 believed to be the only relief, and, as this operation is critical and 

 can only be performed 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 by 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 

 extent, and the animal appears as if suffocation was imminent. An 

 animal that is a roarer should not be used for breeding purposes. 

 The taint is transmissible in many instances. 



Grunting. A common test used by veterinarians when exam- 

 ining 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 com- 

 mon 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, or rheumatism, and other affections accom- 

 panied with much pain, will grunt when moved, or when the pain 

 ia aggravated, but grunting under these circumstances does not 



