DISEASES or THE RESl'lRATORV ORGANS. 129 



fii*st. In tliis variety the air find^; its way into the liinp tissue be- 

 tween the ail" cellis or the tissue between the small lobules. 



Symptoms. — Almost every experienced horseman is able to detect 

 hea\es. The peculiar movement of the flanks and abdomen jjoint out 

 the ailment at once. In recent cases, however, the atleitetl aninud 

 does not always exhibit the characteristic breathing unless exerted 

 to a certain extent. The cough which accompanies this disease is 

 peculiar to it. It is ditlicult to dcsciibe, but the sound is short and 

 something like a giunt. A^'hen air is inspired — that is, taken in — it 

 appears to be done in the same manner as in health; it may i)o.^sibly 

 be done a little (luick'cr than natural, but not enough to attract any 

 notice. It is when the act of expiration (or expelling the air from 

 the lungs) is performed that the great change in the breathing is 

 perce|)tible. It nuist be remembered that the lungs ha\e lf)st much 

 of their elasticity, and in consequence of their power or contracting 

 on account of the degeneration of the walls of the air cells, and also 

 on account of the pai'alysis of muscular tissue before mentioned. 

 The air passes into them freely, but the power to expel it is lost to 

 a great extent by the lungs: therefore the abdominal muscles are 

 brought into play. These muscles, especially in the region of the 

 flank, are seen to contract, then pause for a moment, then complete 

 the act of contracting, thus making a double bellowslike movement 

 at each expiration, a sort of jerky motion with every breath. The 

 double expiratory movement may also be detected by allowing the 

 horse to exhale against the face or back of the hand. It will be ob- 

 served that the exi)iratory current is not continuous, but is broken 

 into two jets. When the animal is exerted a wheeezing noise accom- 

 panies the breathing. This noise may be heard to a less extent when 

 the aninud is at rest if the ear is applied to the chest. 



As before remarked, indigestion is often present in these cases. 

 The animal nuiy have a depraved appetite, as shown by a desire to 

 eat dirt and soiled bedding, which he often devours in preferencce 

 to the clean feed in the trough or manger. The s-tomach is liable 

 to be overloaded with indigestil)le feed. The abdomen may assume 

 that form called "potbellied." The animal frequently passes wind 

 of a very offensive odor, ^^'hen first put to work dung is passed 

 frefjuently: the bowels are often loose. The animal can not stand 

 much work, as the mu.scular .sy.stem is soft. Kound-chested hor.sef 

 are said to l3e predisposed to the di.sease, and it is certain that in 

 cases of long standing the chest iisiudly becomes rounder than natura]. 



Certain individuals become very expert in managing a horse af- 

 fected with heaves in suppressing the symptoms for a short time. 

 They take advantage of the fact that the breathing is much easier 

 when the stiunach and intestines are empty. They al.so resort to the 

 30444"— IG 9 



