Occurrence: Worldwide. Species affected: Mostly turkeys, occasionally in chicken, quail, pheasants, grouse, chukar partridges, guinea fowl. Age affected: Young.

Causes: Amoeboid protozoan Histomonas meleagridis.

Effects: Enterohepatitis has a 7-12 day incubation period. In chickens, morbidity (to 100%) occurs, a cyanotic head and bloody caecal diarrhoea. In turkeys, signs include drowsiness, drooping of wings, stilted gait, closed eyes, head ...

Histomoniasis or Blackhead disease caused by Histomonas meleagridis is a re-emerging disease in poultry and may invade tissues other than the caeca and liver. The ban of effective drugs has led to new insights into the disease and alternative ways to protect the birds