DISEASES OF THE HORSE. 521 



Terminations. — These symptoms may gradually subside after five 

 to eight days, with an improved appetite the inanition may cease and 

 the animal commence to nourish its impoverished blood and tissues; 

 the pulse becomes stronger and the heart more regular and less tumul- 

 tuous; the mucous membranes assume a brighter and more distinct 

 color; the difficult}^ of respiration is removed, and the animal may 

 make a recovery. When death occurs it is usuall}^ directly due to 

 heart failure; in some cases it is caused b}^ asphyxia, owing to the 

 great amount of exudation into the lung tissue, rendering its further 

 function impossible. 



Complications. — The pulmonary complications of edematous pneu- 

 monia are secondary inllammator}^ or necrotic changes in the lungs 

 themselves. Suppuration at times takes place in the bronchi and may 

 extend to the lung tissue. In this case mucous rales develop which are 

 most distinctly heard over the trachea and on the sides of .the chest 

 directly behind the shoulders. With the development of the mucous 

 rales, to be heard on auscultation, we have a more purulent discharge 

 from the nostrils, similar to that of a chronic or subacute bronchitis. 

 If the inflammation has been of some standing, cavernous rales may be 

 heard indicating the destruction of a considerable portion of lung tissue 

 arid the formation of a cavity. The effects of this more acute inflamma- 

 tor}'- process are not appreciable in the general condition of the 

 animal, except to still further weaken it and add to its debilitated 

 and emaciated cachexia. Gangrene sometimes occurs. A sudden 

 rise of the body temperature of 1° or 2", with a more enfeebled 

 pulse and a still more tumultuous heart, develop simultaneously with 

 the appearance of a discharge from the nostrils. This discharge is 

 gray in color, serous or water}' in consistenc}^, mixed with the detritus 

 of broken-down lung tissue, and sometimes contains clots of blood, or 

 in more serious cases may be marked by a quantity of fluid blood 

 from a hemorrhage, which proves fatal. The discharge is fetid to the 

 smell. The animal emaciates rapidly. On examination of the lungs 

 mucous rales are heard in the larger bronchi, cavities maj' be found at 

 any part of these organs, and points of lobular pneumonia ma}- be 

 detected. 



A verj' serious complication is an inflammation of the heart mus- 

 cle. This is shown by a very weak and rapid pulse, great prostration, 

 some filling of the lungs. This complication nearly alwaj'S terminates 

 in death. Other complications which may be mentioned are inflam- 

 mation of the kidneys, blood poisoning, congestion of the brain, and 

 inflammation of the tendinous sheaths and the tendons of the legs. 



Diagnosis. — As fever is the first symptom of edematous pneumonia, 

 it is useful during an outbreak of this disease to make daily tempera- 

 ture measurements of the exposed horses, so that the first indication 

 of disease may be discovered and the horse removed from contact with 

 those that are sound. 



