286 Diseases of Poultry 



very difficult to distinguish them except by prolonged study 

 of their life cycles. 



Various species of coccidia have long been known to in- 

 fest many domestic animals. A number of these have 

 been described in fowls and other birds. In many cases 

 they produce very serious lesions. But the contention of 

 Smith ^ that in many cases these parasites are more or less 

 normal inhabitants of the digestive tract seems fairly well 

 founded. 



Coccidiosis in birds and the relation of coccidia to the 

 disease known as entero-hepatitis have been discussed on 

 pages 71 and 94. On page 73 a detailed description of the 

 life history of a typical coccidium is given. It is supposed 

 that it is the same coccidium causing entero-hepatitis in 

 turkeys which is related to white diarrhea. For further 

 description of this organism the reader is referred to the 

 preceding chapter. 



Hadley and Kirkpatrick * have reported some feeding 

 experiments with these coccidia in which they have been 

 able to produce the disease in chicks several days or weeks 

 old. As will be noted later, it is claimed that infection with 

 the bacterium of bacillary white diarrhea must take place 

 during the first two or three days of the chick's life if it is 

 to produce the disease. It is possible that these facts may 

 be of some use in distinguishing the two forms of this disease. 



Diagnosis. — The symptoms of coccidiosis are similar to 

 those of other forms of white diarrhea (cf. p. 292). The 

 only exception is that according to Morse the ceca are always 

 distended with yellowish-white cheesy matter. In other 



1 Smith, Theobald, " Amceba meleagris." Science, N. S., Vol. 32, 

 pp. 509-512, 1910. 



2 Hadley, P. B., and Kirkpatrick, W. F., "Further Investigations 

 upon White Diarrhea of Chicks." Successful Poultry Jour., Vol. 14, 

 pp. 18-19, 1909. 



