Prevention. ggo 



should be made to remove all affected horses as soon as possible. 

 This is usually carried out easily in sporadic occurrences of 

 the disease or in localities where horse insurance is maintained. 



Immunization. The experiments which have been undertaken by Carre & 

 Yallee along this line with the blood of apparently recovered animals, also with 

 blood from donkeys or cattle which have been inoculated repeatedly with virulent 

 material, were unsatisfactory; likewise Marek 's experiments with the blood of an 

 apparently recovered horse or with blood exposed to various high temperatures, 

 or which had been treated with a trichloride of iodine solution. 



Literature. Brickmann, D. t. W., 1907. 724. — Carre & Yallee, Eev. gen., 

 1906. VIII. G93; 1907. IX. 113 (French Lit.). — Ekvall, Tidsskr., 1895. 208. - 

 Francis & Marsteller, Texas Agricult. Exper. Station, 1908. — Frohner, A. f. Tk., 

 1886. XII. 382. — Hempel, Z. f. Infkr., 1909. V. 381 (Lit.). — Hochstein, W. f. 

 Tk., 1907. 145. — Jarmatz, Z. f. Vk. 1904. 68. — Kopke, Z. f. Vk., 1901. 356. — 

 Meier, Z. f. Tm., 1906 X. 1. — Mohler, The Vet. Journ., 1909. 395. — Ostertag, 

 Monh., 1890. I. 127; Z. f. Infkr., 1907. III. 1. — Eies, Eec, 1908. 11. — Vallee, 

 Bull, 1907. 526. — Zschokke, Sehw. A., 1883. XXV. 11. 



3, Progressive Pernicious Anemia. Anaemia Perniciosa 

 Progessiva. 



By the name of progressive pernicious anemia is designated 

 in human medicine a severe and gradually x^rogressing' anemia, 

 with the appearance of gigantocytes and gigantoblasts in the 

 blood (Ehrlich) or with a change in the proportion between 

 the hemoglobin content and the number of blood corpuscles 

 in favor of the blood coloring matter (Tallquist), in which 

 the form of the red blood corpuscles undergoes conspicuous 

 changes. The disease appears w^ithout any apparent cause 

 (cryptogenetic form of pernicious anemia) or in connection 

 with certain organic diseases (secondary form of pernicious 

 anemia). 



History. The disease was first described in human medicine in 

 1868 by Biermer, but was mentioned previously already as idiopathic 

 anemia by Lebert and Addisson. Since that time the disease has 

 been observed in a large number of cases in certain localities, especially 

 in Switzerland, England and Sweden. There exist several publica- 

 tions relative to the occurrence of pernicious anemia in animals, but 

 most of them probably allude to the infectious anemia of horses, which 

 is a specific infectious disease, and according to the blood findings 

 does not correspond with the progressive pernicious anemia (see p. 851). 

 Regarding the few remaining cases it is undecided whether they should 

 ])e considered as pernicious anemia, because in these cases the diagnosis 

 was based only on the severity of the anemia and on the demonstration 

 of a poikilocytosis, which however cannot by any means be considered 

 as a proof of the pernicious nature of the anemia, since the poikilocytosis 

 may represent artifacts (see p. 857). At any rate it remains for 

 thorough hematological investigations to decide how frequently true 

 progressive pernicious anemia occurs in domestic animals. 



Etiology. Nothing positive can be said at present relative 

 to the cause of primary crj^togenetic pernicious anemia. 

 Human physicians frequently associate the origin of the disease 



