110 



POULTRY DISEASES 



of the left side (artery to left leg). Upon micro- 

 scopic examination they were found to be white 

 thrombi. Fig. 39 illustrates this condition. It 

 may be seen that the blood vessels are quite dis- 

 tended by the blood fibrin. 



Spirochetosis 



This is a blood disease (septicemia) due to a' 

 spiral-like microsco])ic germ which is supposed to 



be carried from 

 bird to bird bv 

 means of the 

 chicken tick; illus- 

 trated in Fig. 16. 

 Fig. 40 shows a. 

 drawing of the 

 g e r m. It is the 

 SpirocJieta gallin- 

 arum; the slide 

 from which this 

 drawing was made 

 was kindly sent 

 to the author by 

 Dr. Balfour of 

 Khartoum, Sudan, 

 Africa. 



This disease was 

 first recognized in Brazil; it is found in Africa 

 and Europe. A disease occurs in the southern 

 part of the United States, where the chicken tick 

 is abundant, that presents symptoms similar to 

 those of spirochetosis; so far as the author 

 knows, no definite work has been done to deter- 

 mine the true cause of it. 



Spirochetosis is most common among chickens, 

 but also infects geese, ducks, pigeons and spar- 

 rows. 



Fig. 39. Thrombosis in a Hen 



A, Pelvis bone, central portion. B, muscle 



of thigh. C, blood vessel containing 



a white thrombus. 



