DISEASES OF THE DIGESTIVE TRACT 89 



color ; there is a loss 

 of appetite; the bird 

 grows gradually 

 weaker and usually 

 dies in from three to 

 ten days after the 

 first symptoms of the 

 disease become no- 

 ticeable. In the cases 

 that run longer the 

 bird becomes emaci- 

 ated. A blood exami- 



FiG. 30. Blood Smear (from a Case 



of Blackhead) — 



Showing intense eosinophilia. a, Red natinn <J>in-w« pnainn 



blood cells. b, eosinophiles. c, ^'^'-iOn bUOWb eOSlUO 



thrombocytes, d, lymphocytes. e, 

 mononuclear leucocytes. 



philia to be present. 



he head may or may 

 not turn purple. From the cases in which the 

 head turns purple the disease gets its name — 

 blackhead. 



Report of a Case of Blackhead 



Of eleven turkeys of the flock, six had died. One of the 



Fig. 31. Section of a Kidney 



From a turkey that had died of blackhead, a, Cloudy 



swelling, b, area of focal necrosis. 



turkeys was brought to the laboratory for further study. 

 The turkey's head was purple; there was a loss of appetite; 



