186 



Influenza of Horses. 



In the Prussian army in the years of 1899 to 1908, among 9,925 affected 

 animals tendonitis and tendo-vaginitis (724 cases), roaring (330), internal opthalmia 

 (189), purpura hemorrhagica (53), skin ei-uptions (62), inflammation of joints (32), 

 etc., occurred as the most frequent complications, or sequelae of contagious pleuro- 

 pneumonia. 



Course. The catarrhal form of influenza lasts in the great 

 majority of cases about one week, sometimes, however, only 

 two to three days, in which cases the fever rapidly subsides, 



and the animals soon 

 recover. In other 

 cases the course may 

 extend to two weeks, 

 and then it requires 

 considerable time un- 

 til the animals regain 

 their health. Fatal 

 terminations are ex- 

 ceptional, and only 

 occur when severe 

 complications become 

 associated with mild 

 forms of the affec- 

 tion (pneumonia, hy- 

 peremia or acute in- 

 flammation of the 

 brain, enteritis, de- 

 generation of the 

 heart muscle, etc.). 



Much more va- 

 ried is the course of 

 the pectoral form of 

 influenza. In the 

 typical cases in which 

 the different stages 

 of lobar pneumonia 

 follow each other 

 with regularity, and 

 the resolution is also 

 undisturbed, the 

 pleurisy being pres- 

 ent in a mild form or 

 not demonstrable at 

 all, the fever may 

 subside at the end of 

 the first or at the be- 

 ginning of the second week. Here, however, complications and 

 sequelae which develop frequently in association with the dis- 

 ease, more often cause a deviation of its regular course. 

 Especially in cases of pleurisy in which a great quantity of 

 exudate develops, the affection may extend for weeks (Fig. 37), 

 and even for months, the patients manifesting temporary im- 



