382 ENTERO-HBPATITIS IN TURKEYS 



pies the most prominent place among the objective manifesta- 

 tions. The disease of the ceca is presumably responsible for 

 this. Diarrhea occurs with at least one other disease of the 

 ceca and with the presence of tapeworms. Emaciation is pro- 

 nounced in very chronic cases but it is uot constantly present. 

 As it may accompany other wasting diseases, it can not be de- 

 pended upon as an indication of this affection. As the disease 

 progresses the turkeys become less active, lag behind their 

 flock or do not go out with it. Later the comb, wattles and 

 even the skin of the head become dark colored, hence the 

 popular name "blackhead." 



§ 301. Morbid anatomy. Turkeys are attacked quite 

 young. Smith found a turkey about three weeks old in which 

 the disease had already made considerable progress. It seems, 

 moreover, as if the disease is contracted only by the young, 

 because in the examination of turkeys of different ages the 

 oldest show lesions of the Ipngest standing ; that is, such as 

 had undergone the most extensive transformation. In general 

 it may be said that the age of the turkey corresponds with the 

 age of the disease process. The most serious and extensive 

 destruction of tissue occurs in the turkeys in the fall. In mid- 

 summer the disease is making most progress and the micro- 

 parasites are present in greater numbers. .It is probable that 

 the delicate tissues of the young are best adapted for the tem- 

 porary habitat and rapid multiplication of this parasite.* 



The primary seat of the disease is the ceca. From these 

 the liver is secondarily invaded. Other organs have not been 

 found to be attacked. 



The lesions of the ceca are in substance a thickening of 

 the wall, followed in most cases by a destruction of the 

 epithelium and deeper portions of the mucous membrane. 

 This destruction results in the outpouring of a coagulable 

 fluid into the tube. The thickening of the wall may vary 

 considerably in extent from case to case. 



'In this regard it simply follows the rule observed by large numbers 

 of parasites whose most destructive action is visited upon the young. 



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