Thought to have been brought into the U.S. in imported ringnecked pheasants. Domestic chickens and related birds. A flagellate protozoan, Histomonas meleagridis is transmitted within nematode eggs which causes a serious disease in turkeys. Adult nematodes are in intestine of turkey. Nematode eats protozoan which multiplies in the worm's intestinal cells, in the ovaries, and in the embryo within the egg.
Eggs pass with feces.
Eggs hatch after being eaten and release Histomonas . One parasite acts as an intermediate host and vector of another. Eggs may also be eaten by an earthworm, the juvenile may hatch and become dormant in the worm's tissues for at least a year. Since the nematodes do not develop further until eaten by a bird, the earthworm is a paratenic host. Feeding mebendazole routinely in feed or water.