ASTHMA AND BROKEN WIND. 169 



affected with this disease than better bred horses which are 

 more carefully attended to. 



Professor Eobertson says that chopped hay is especially 

 liable to^, induce broken wind, and has noticed in some 

 districts that while the agricultural horses were fed on oats, 

 with hay or oat straw, the fodder being given in full supply, 

 broken wind was unknown, but that when the extensive 

 use of chopped hay and oat-straw was adopted, this disease 

 became comparatively common. 



(3.) Changes left by Previous Diseases. — Those changes 

 in the lung tissue which arrest the contractile power and 

 action of pulmonary air-tubes may cause broken wind. 



Symptoms. — The symptoms in confirmed cases of broken 

 wind are unmistakable, but when not so fully developed 

 the disease may be occasionally overlooked. 



The inspiratory movement is performed rather quickly 

 and with ease. The expiratory movement is much pro 

 longed, difficult, and accomplished by two apparent efforts. 

 It begins by a rapid contraction and upward movement of 

 the posterior walls of the abdomen, and is suddenly stayed 

 before the act is completed, and then continued slowly by 

 an upward and forward movement of the abdominal 

 muscles. 



The cough of broken wind is characteristic, being short, 

 of little force, and suppressed, and seems to be ejaculated 

 with a kind of grunt through the upper part of the trachea 

 (Blain). AVhen the animal is in fair condition, the cough 

 generally occurs only at long intervals, and rarely in 

 paroxysms ; but at the commencement of the disease, and 

 when the horse is excited from any cause, or during exer- 

 cise, it is apt to break out in paroxysms. 



In many instances cough is one of the first indications of 

 broken wind. 



After feeding, the symptoms are more severe, and they 



