Pro,i;nosis. Tceatineiit. Jnterstitial Eiupliyseuia of the Lungs. 99 



Prognosis. It is impossible to prevent the progressive 

 development of the disease; the prognosis therefore is un- 

 favorable as to complete recovery. Since, however, the develop- 

 ment goes on very slowly, the animals may occasionally be 

 serviceable for years for walking and for pulling moderate 

 loads. The degree of the diminution of the ability to work 

 must be ascertained by actual tests. 



Every complication which appears during the course of 

 the disease influences the prognosis unfavorably. This is 

 particularly true of bronchial catarrh which is seen so fre- 

 quently as a complication ; its complete cure will be much re- 

 tarded in consequence of the insufficient exchange of gases. 

 Cardiac weakness is of similar unfavorable prognostic signifi- 

 cance. 



Treatment. Good nutrition and appropriate work may be 

 relied upon in the absence of any specific curative treatment 

 to prolong the period of usefulness of the animals. Complica- 

 tions which may arise, especially bronchial catarrli, must be 

 properly treated (see page 61). 



The systematic administration of arsenic (0.1-0.5 gni. pro 

 die) is generally indicated in affections of this kind which are 

 characterized by an asthmatic condition. The beneficial effect 

 of arsenic depends on its improvement of the nutrition. The 

 authors have found intratracheal injections of strychnine use- 

 less. Equally doubtful is the value of vergotinin (in teaspoon 

 doses), a mixture of veratrin, strychnine, ergotin and glvcerin. 

 Uhland injected daily 5-10 gm. of a 1% solution of atropine and 

 obtained only a temporary improvement (see page 97). Cau- 

 tion is indicated in the use of eserine or chloride of ])arium 

 in horses with emphysema, since in consequence of contraction 

 of the muscle fibers of the bronchi these drugs may increase 

 the dyspnea and even lead to suffocation, as shown by the 

 experiments of Raitsits. 



Literature. Bouley, Diet., 1S7S, V, 484.— Delafond, Eec, 18a7, 243.— Griiter, 

 Beitr. z. Kenut. d. Broiich. ehroii. des Pferdes, Diss. Ziirich, 1909. Holterbach, 

 B. t. W., 1905, 425.— Eichter, A. f. Tk., 1905, XXX, 576.— Schmidt, Naturf. Vers. 

 Dresden, 1907.— Stommer. D. Z. f. Tm., 1887, XIII, 93. 



4. Interstitial Emphysema of the Lungs. Emphysema pul- 

 monum interstitiale. 



Interstitial pulmonary emphysema consists in the accumu- 

 lation of atmospheric air in the intra- and interlobular con- 

 nective tissue of the lungs after solutions in the continuity 

 of the alveolar walls. 



Etiology. Every considerable increase of the air pressure 

 in the lungs, particularly if occurring suddenly, may directly 



