Fowl Cholera, Foicl Typhoid and Fowl Plague 113 



that considerable work has been done upon fowl plague, com- 

 paratively little is known about it. The following notes are 

 gathered from such literature as is at hand. 



Etiology. — No definite organism has ever been isolated in 

 connection with this disease. Depperich ^ stated (1907) that 

 all the then available evidence indicated that it is caused by 

 an ultra-microscopic, filterable virus. Russ ^ states that the 

 blood from cases of this disease is extremely virulent, being 

 fatal when given in such extreme dilution as 1 to 1,000,000,000. 

 The virus of this disease appears to be in some way attached 

 to or included in the red blood corpuscles. By centrifuging 

 out these corpuscles it is possible to remove a large portion 

 of tlie virus from the blood. Landsterner ^ performed cer- 

 tain experiments which indicated that the causative organism 

 may be a protozoon associated with the blood corpuscles. 

 In this respect the causative factor in the disease appears to 

 show some resemblance to the filterable virus of hog-cholera, 

 according to recent work.^ 



Diagnosis. — Fowl plague is known to affect chickens, tur- 

 keys, guinea-fowl, geese, pheasants, and many wild birds. 

 The lesions of the disease resemble those produced by phos- 

 phorous poisoning.^ The surface of the heart may be covered 

 with small blood clots (ecchymoses). It can be distinguished 

 from fowl cholera by the presence of hemorrhages under the 

 epicardium and an exudate in the pericardial cavity. 



1 Depperich, C. H., Fortsch. Vet. Hyg. Bd. 4, pp. 217-250, 

 1907. 



2 Russ, V. K., Arch. Hyg. Bd. 59, pp. 286-312, 1906. 



^ Landsterner, K., Centralb. f. Bakt., etc., Abt. 1, Bd. 38, pp. 

 540-542, 1906. 



^ For example : 



King, W. E., and HoiSman, G. L., "Studies on Hog Cholera — 

 Spirochceta suis. Its Significance as a Pathogenic Organism." 

 Jour. Infec. Dis., Vol. 13, pp. 463-498, 1913. 



^ Freese, Deiit. Tierarztl. Wchnschr. Bd. 16, pp. 173-177, 1908. 



