CHRONIC DISEASES OF THE ORGANS OF RESPIRATION. 227 



When, however, this affection accompanies or rather is the result of 

 serious derangement of the Pulmonary system, such as Broken Wind, it 

 is obviously incurable, because the cause, from which it proceeds, is 

 incurable. 



THICK WIND. 



452. Nature and causes of Thick Wind. 



Thick Wind generally arises from thickening of the mucous membrane 

 of the finer bronchial tubes and air cells, caused by acute or chronic 

 inflammatory disease either of the bronchial tubes or of the lungs. In 

 the latter case the bronchial tubes are also usually involved. It may 

 also be produced by injudicious and violent exercise after watering, or 

 when the stomach is full, or when the animal has been kept on soft 

 food. It is also found in horses of a pampered plethoric habit. In 

 these cases it is probably due to nervous irritability of the lungs, sym- 

 pathising, as they readily do, with the condition of the stomach. 



On account of the thickening of the mucous membrane the horse 

 labours much in his breathing, especially when the respiration is ac- 

 celerated by work. The importance or otherwise of this disease mainly 

 depends on the degree of thickening which has taken place and the 

 extent of lung affected. These points can in some measure be ascer- 

 tained by auscultation over the region of the chest, after the horse has 

 been made to exert himself. This disease is distinguished from Broken 

 Wind by the inspirations and expirations being performed with equal 

 quickness. 



453. Treatment. 



Treatment can only be palliative. Active measures are useless. 

 Good condition, regular work, and very careful watering and feeding 

 will mitigate the evil. When, however, the disease arises from a 

 plethoric state, medicine either purgative or diuretic is useful. Exer- 

 cise and an occasional sweat will also be needed. 



Fat young horses made up for sale are often affected in their breath- 

 ing to an extent which may easily be mistaken for thick wind ; but in 

 such cases moderate diet, exercise, and a course of physic will generally 

 be sufficient in a short time to relieve the symptoms. 



ROARING. 



454. Nature and seat of Roaring. 



Roaring is a very peculiar noise made usually in the act of inspiration, 

 especially when the breathing is accelerated. In some cases it may be 

 made both in expiration and inspiration. The sound is caused by 



