138 DISEASES OF THE HOESE. 



formed that the great change in the breathing is perceptible. It must 

 be remembered that the lungs have lost much of their elasticity, and, 

 in consequence, of their power of contracting on account of the de- 

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

 paralysis 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 observed that the expiratory current 

 is not continuous, but is broken into two jets. When the animal is 

 exerted a wheezing noise accompanies the breathing. This noise 

 may be heard to a less extent when the animal is at rest if the ear be 

 applied to the chest. 



As before I'emarked, indigestion is often present in these cases. 

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

 dirt and soiled bedding, which he often devours in preference to the 

 clean food in the trough or manger. The stomach is liable to be 

 overloaded with indigestible food. The abdomen may assume that 

 form called " potbellied." The animal frequently passes wind of a 

 very offensive odor. When first put to work dung is passed fre- 

 quently ; the bowels are often loose. The animal can not stand much 

 work, as the muscular system is soft. Eound-chested horses are said 

 to be predisposed to the disease, and it is certain that in cases of long 

 standing the chest usually becomes rounder than natural. 



Certain individuals become very expert in managing a horse 

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

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

 when the stomach and intestines are empty. They also resort to the 

 use of medicines that have a depressing effect. When the veterina- 

 rian is examining a horse for soundness, and he suspects that the 

 animal has been " fixed," he usually gives the horse as much water as 

 he will drink and then has him ridden or driven rapidly up a hill or 

 on a heavy road. This will bring out the characteristic breathing 

 of heaves if the horse is so afflicted, but will not cause the symptoms 

 of heaves in a healthy horse. All broken-winded horses have the 

 cough peculiar to the affection, but it is not regular. A considerable 

 time may elapse before it is heard and then it may come on in 

 paroxysms, especially when first brought out of the stable into the 

 cold air, or when excited by work, or after a drink of cold water. 

 The cough is usually the first symptom of the disease. 



Treatment. — When the disease is established there is no cure for it. 

 Proper attention paid to the diet will relieve the distressing symp- 



