Histomoniasis(redirected from avian blackhead)
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a parasitic disease of turkey chicks and less frequently of chickens, characterized by purulent inflammation of one or both ceca and affection of the liver. The disease is caused by protozoans—histomonads (Histomonas meleagridis). It is ubiquitous.
Mass infection of the young occurs when they are kept together with adult fowl, whose feces often contain ova of helminths of the genus Heterakis, which are infested with histomonads. Histomoniasis is fostered by crowding the chicks, disruption of their heat and light conditions, poor feeding, dampness, and poor cleaning. Usually, on the second to fourth day infected chicks develop foul-smelling diarrhea. In many, the skin of the head darkens (hence the English name of the disease—blackhead). The turkey chicks die within one to three weeks. Diagnosis is based on clinical and epizootological data and the results of laboratory tests. Furazolidone, osarsol, enteroseptol, antibiotics, and other preparations are used in treatment. Recommended preventive measures include raising chicks on screened or latticed floors and isolating them from adult fowl.