6 



One has only to attend a conference of turkey fanciers to 

 witness the confused state of the present knowledge. Many 

 pet theories are propounded, and numerous preventives and 

 cures for any and all symptoms are advocated, but there is an 

 obvious dearth of real information on the fundamental prin- 

 ciples underlying the problem. This is not to be wondered at 

 when it is appreciated that the most important difficulty in 

 turkey raising results from a disease which in many respects is 

 quite unlike any other known disease of man or animals. In 

 fact, it has baffled scientific investigation for many years, and 

 while it is now fairly well understood, there are still certain 

 points which have yet to be satisfactorily explained. Not- 

 withstanding the variety of views and conflicting opinions, 

 there is general agreement that this very fatal disease, com- 

 monly known as blackhead, is a most important obstacle to 

 turkey raising. 



Undoubtedly this disease often exists without being recog- 

 nized. Without careful observation there is nothing very dis- 

 tinctive in the symptoms of the infection, and although the 

 appearance of the liver and certain portions of the gut are 

 quite characteristic, there is often no time or inclination to 

 open a dead turkey and examine the internal organs. Of 

 course turkeys may die from other causes, especially when 

 very young, but it is usually found that when they die under 

 apparently good conditions blackhead is present. That this 

 disease causes 90 per cent of the losses in growing turkeys is 

 probably not an overestimation. 



This being the case, w^e wull first outline what is at present 

 known of this disease, and then discuss those conditions which 

 favor successful turkey raising. 



Blackhead. 

 This name is not especially appropriate for the disease in 

 question, but has been retained for want of a more satisfactory 

 term. It was doubtless applied on account of the change in 

 color from the normal red of the head in health to a bluish or 

 dusky color which usually occurs in sickness. This, however, 

 varies with the degree of pallor, so that no great reliance should 

 be placed upon head color alone as evidence of disease. To 



