Dr. Kassai Tibor szerk.: Parasitologia Hungarica 1. (Budapest, 1968)

distinct and a thin, filament was seen to connect its border with the body of the parasite. The morphological appearance and particularly the filament suggested the parasite to be a Histomonas meleagridis In healed lesions the liver cells were arranged more densely and their nuclei stained darker with hematoxylin than did healthy liver tissue (Pig. 6). In addition, a few residual granulocytes and structures resembling the parasites were encountered in paler areas where the liver trabeculae had been replaced by disorderly aggregates of liver cells. Thus histological examination failed to provide evidence as to the precise nature of the etiological agent of blackhead. The PAS-positive structureless organisms were probably fungi, whereas the pale pink structured organisms closely resembled H. meleagri- dls

. It seems feasible, therefore, that both organisms and, according to more recent findings, even certain bacteria, play a role in the causation of blackhead (TAIL and PRAKKER, 1963). 3-)Action of Hepamix. Mixed in the diet of turkey flocks severely affected with blackhead (10-20 $> losses), 1 $> Hepamix feed additive stopped the outbreak in 5 days

. later deaths were mostly due to intercurrent diseases. Given in the initial stage of the outbreak, treatment with H ep a m I X minimized losses. Naturally

,early medication requires early correct diagnosis. The experienced veterinarian, and even technical assistants can recognize blackhead by the clinical symtomps prior to occurrence of losses. Diseased birds lose Pig. 4. Histomonas-like parasites- in the liver of a turkey affected with blackhead. Adjacent to the nucleus rubin granules are apparent. Oilimmersion. X 1500 Histomonas-szerü élősködők blackheades pulyka májában. A mag mellett a rubinszemcsék is feltűnnek. Immerziós felvétel. 1500 X