)84 



ENTERO-HEPATITIS IX TURKEYS 





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spaces, by virtue of which the mucous membrane is thickened. 

 In this early stage of invasion the epithehum, both of the 



tubules and of the surface, remains 

 unaffected. The parasites do not 

 invade the epithelium at any time. 

 As the disease progresses there 

 is a continued increase in cellular 

 elements of the mucous and sub- 

 mucous coats and a gradual inva- 

 sion of the muscular coat. Here 

 the bundles of fibers of the circular 

 coat are thrust apart by masses of 

 cells, so that this coat also becomes 

 greatly thickened. The inflamma- 

 tion finalh' extends to the serous 

 covering, where the blood vessels 

 become greatly dilated and give the 

 cecum a congested appearance. In 

 cases of ordinary severit}- the wall 

 of the cecum which is not more 

 than 0.2 to 0.5 mm. thick normally 

 becomes 2 to 3 mm. thick. 



With the progress of the dis- 

 ease the mucous membrane may be 

 shed and a coagulable fluid poured 

 out into the cecum. In some cases 

 it appears in isolated masses, which 

 adhere to certain spots of the mu- 

 cous membrane. In others, this 

 exudate fills the entire tube with a 

 yellowi.sh-white mass, built up in 

 concentric layers consisting of a 

 mixture of blood corpuscles, fibrin 

 and small round cells in variable 

 proportion. 



In the further progress of the local disease it is not im- 

 probable that bacteria are also concerned. The exudate con- 



FiG. 100 Diseased cecum, 



showing thickness of wall 



and ulcerated mucosa. 



