376 DISEASES OF BREATHING. 



SYMPTOMS. — When breathing, while the animal is at rest, air 

 is taken into the lungs in a more or less normal manner, but is 

 expelled from them by two distinct efforts, the muscles of the 

 abdomen forcibly aiding the completion of the act of expiration, 

 as is made apparent by the heaving of the flanks; the ribs being 

 comparatively little used for breathing by a broken-winded horse. 

 Note that, when a healthy animal is at rest, there is only one 

 effort made in expelling air from the lungs; for tranquil and 

 natural expiration is a passive act of elastic recoil. From exercise, 

 the difficulty of breathing increases out of all proportion to the 

 amount and nature of the work, and the duration of the act of 

 expiration is longer than that of inspiration; the contrary of this 

 being the case in health. At the commencement of the attack 

 there is a spasmodic cough, which is more or less intermittent. 

 Later on, it becomes a single, weak; short, and suppressed cough, 

 as if the animal had not power in his chest to give a full one, and 

 is often accompanied by -expulsion of wind from the anus, which 

 is more or less protruded. The difficulty of breathing (except at 

 first, when there are remissions) is constant, and increases in 

 proportion to the amount of food in the stomach and intestines. 

 The digestion and general health of animals affected are usually 

 much out of order. Broken wind may come on suddenly. 



CAUSES. — This disease appears to be generally brought on by 

 putting the animal to hard work when his stomach and intestines 

 are distended with food, or when he is suffering from diseases of 

 the drgans of breathing; or by neglect of such diseases. The 

 consumption of unsuitable food (such as chopped straw, hard and 

 innutritious hay, and over-ripe rye grass), often regarded as the 

 exciting cause, has, in all probability, only a predisposing induence, 

 which is a remark that is undoubtedly true with respect to roaring 

 (p. 378). In New Zealand, where this disease is not uncommon 

 among horses kept in the open, it is said, that no one has 

 produced this condition experimentally by feeding. In all cases 

 there was some history of a cold which never seemed to leave or 

 become entirely absent, and as no rational attempt was ever made 

 to treat these cases when suffering from cold, or even to house 

 them, it is no wonder that permanent lesions, such as pulmonary 

 emphysema, resulted. 



The predisposing influence of heredity is said to be well marked 

 in this disease. Some authorities assert that broken-winded mares 

 are almost always barren. 



TREATMENT. — As broken wind is incurable, the treatment can 

 only be palliative. Feed and water by small quantities at a time. 



