Prevention, Veterinary Police. 835 



characteristic of the disease, as well as the possibility of a 

 healthy stallion transmitting the disease from an affected mare 

 to a healthy animal, appear to justify an action requiring that 

 healthy stallions which have covered mares affected with dourine 

 should be considered the same as those affected. 



Literature. Hertwig, Mag., 1842. VIII. 269; 1847, XIII. 373. — Eouget, 

 A. P., 1876. 717. — Schneider & Buffard, Eec, 1900. 81; J. vet., 1902. 144; A. P., 

 1905. XIX. 715. — Marek, Z. f. Tm., 1900. IV. 401; D. t. W., 1909. 121. — Kern, 

 Z. f. Tm., 1905. IX. 259. — Lingard, Cbl. f. B., 1904. XXXVII. 537. — Baldrey, 

 J. of comp. Path., 1905. XVIII. 1. — Sieber & Gonder, A. f. Schiffs- ii. Trophyg., 

 1908. XII. 246. — Uhlenhuth & Woithe, Arb. d. G.-A., 1908. XXIX. 403 (Lit. on 

 chemotherapy). — Frohner, Monh., 1909. XX. 385. — Zwick. D. t. W., 1910. Nr. 9 

 Beibl. 



(d) Mai de Caderas. 



History. The etiology of the disease (Mai de caderas=hip disease) 

 was cleared up by Elmassian, when in 1901 he found trypanosomes in 

 the blood of horses at Argentine. Voges, Zabala and Lignieres con- 

 firmed the finding, and furnished further contributions on the etiology 

 as well as symptomatology of the disease. 



Occurrence. Until the present time the disease has been 

 diagnosed exclusively in the sub-equatorial countries of South 

 America: Brazil, Argentine, Bolivia and Paraguay, as well as 

 on some islands of the delta of the Amazon River. 



According to Lacerda the disease is supposed to have been introduced from 

 the islands of Marajo, westward and southward, and resulted in some localities 

 of Brazil in a complete annihilation of the horses. There are marshy localities in 

 Argentine in which up to 25% of the horses die, and it is stated that a cavalry 

 regiment lost 100 out of 600 newly purchased hordes within half a year (Voges). 



Etiology. The trypanosoma 

 equinum (Th. Elmassiani) is similar 

 to the parasite Of nagana, with the 

 only difference that its blepharoplast 

 is very small and can be stained only 

 with difficulty (Lignieres; Fig. 150). 



Ruminants and hogs are only 

 slightly susceptible to artificial infec- 

 tions; other animals have about the 

 same susceptibility as for the organ- 

 ism of nagana. In horses infected 



SUbcutaneOUSly with blood disturb- Fig- l^O. Trypanosoma equi- 



ances in locomotion dpvplnn in tbp num s. Elmassiani. Guinea pig 

 ances m lOCOmOIlOn aeveiop m tne blood; stained after Romanow- 



later stages or the disease m a strik- sky-zieman. 

 ing manner (similarity with dourine). 



The disease cannot be reproduced, even in susceptible animals, 

 by feeding fresh blood containing numerous parasites (Zabala). 

 Animals immunized against nagana or surra are still suscep- 

 tible to caderas and vice versa. 



