Diseases Due to Mistakes in Feeding. 221 



Heaves, or broken wind, is a chronic condition in which 

 there is difficulty of breathing, the act of expelling air 

 from the lungs taking longer than the act of breathing in 

 air, it is due originally to mistakes in feeding, and an ani- 

 mal badly aifected is rendered almost incapable of work. 



The difficulty of breathing in this disease is due to a 

 dilated condition of the lungs, owing to excess of air in 

 the air sacs or in the tissue that surrounds the lobules, 

 as a result the lungs are prevented from expelling all the 

 air they should, hence less is taken in than would be if 

 they were in a natural condition. The air cells may be 

 broken into one another as a result of the violent cough- 

 ing, whereas in the other form the air seems to enter the 

 tissues during the intake of air into the lungs, in which 

 case some degeneration has in all probability taken place 

 in the lung tissue. A full stomach and bowds interfere 

 greatly with the action of the lungs, and when filled out 

 with food it is not surprising that this trouble occurs. At 

 the commencement of the disease there is a spasmodic 

 cough, later a suppressed short weak cough, with a double 

 expiration, and the passage of wind by the anus. In ordi- 

 nary breathing no aid is needed to expel the air, the 

 natural elasticity of the lungs performs the work, in this 

 disease the muscles of the abdomen are used, as is no- 

 ticed by the heaving of the flanks. 



While the causes of the previous troubles have been 

 overloading^the system, the cause of this trouble is more 

 mechanical in its nature and may, owing to the feed that 

 causes it, be a disease of the poor feeder' s horse, founder, 

 big leg, etc. , being diseases of the horse belonging to the 

 heavy feeder. The custom existing among so manyjfar- 



