INFECTIOUS ENTERO-HEPATITIS IN TURKEYS. 



Blackhead. Definition : Infectious protozoan disease of caeca and liver 

 and general toxicaemia. Microbiology : Amceba in caeca, liver, etc. 

 Symptoms : Attacks young, dulness, drooping, ruffling, moping, anorexia, 

 greenish diarrhoea, icteric or dusky mucosae, blackening of gobble, etc. 

 Lesions : Enlarged thickened caeca, epithelial degeneration and desquama- 

 tion, exudation, mottled liver, with giant and round cells and amoebae, de- 

 generation, necrosis, caseation, no abscess. Diagnosis from bacteridian 

 typhlitis or diphtheria. Treatment : Intestinal antisepsis. Prevention : 

 Disinfection of buildings, yards, manure, seclude from other flocks, birds, 

 flies, breed new flock on fresh ground from eggs of affected or other flock, 

 set in incubator or under hens. 



Syno7iym: Blackhead. 



Definition. An infectious disease of turkeys, especially de- 

 structive to the young, due to a protozoon (amoeba nieleagridis), 

 and characterized by inflammatory thickening of the walls of the 

 caeca, diarrhoea, brownish, yellowish or greenish areas of degen- 

 eration of the liver, and congestion with blackish discoloration of 

 those portions of the head which are uncovered by down or 

 feathers. 



Microbiology. The microorganism (amoeba nieleagridis) is 

 found in the thickened walls of the caeca, in the exudate, in the 

 lumen, and in the degenerating patches of the liver. The most 

 common and simple form is that of a rounded body, varying 

 slightly in form., and containing a group of very minute granules 

 situated somewhat eccentrically. They may be enclosed in lymph 

 spaces or less frequently in giant cells, or have portions of broken 

 up cells adherent. Their size varies from 10 to 15^. They may 

 be stained by the following process : Harden in 95 per cent, 

 alcohol saturated with mercuric chloride, then in the same with 

 an equal amount of a 5 per cent, solution of bichromate of potash, 

 and finally in Hemming' s solution. After a day in these solu- 

 tions they are washed for a day in running water, then treated 

 with ascending strengths of alcohol, dried by passing through 

 alcohol and chloroform, imbedded in paraffin, sectioned dry, and 

 stained in Delafield's hsematoxylin and eosin. The spherical or 

 slightly oval amoebae have a homogeneous, bluish red tint, feebler 



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