STATUS OF COMMERCIAL AND NONCOMMERCIAL CHICKENS AS POTENTIAL SOURCES OF HISTOMONIASIS AMONG WILD TURKEYS

Histomoniasis (blackhead disease) is a disease of gallinaceous birds caused by the protozoan Histomonas meleagridis, which is transmitted between avian hosts within the egg of the cecal nematode, Heterakis gallinarum (Reid 1967, Lund and Chute, 1974). Histomoniasis occurs in many species of gallinaceous birds, including wild and domestic turkeys (Meleagris gallopavo), chukar (Alectoris chukar), common peafowl (Pavo cristatus), ruffed grouse (Bonasa umbellus), northern bobwhite (Colinus virginianus), gray partridge (Perdix perdix), guineafowl (Numida meleagris), ringnecked pheasant (Phasianus colchicus), chicken (Gallus gallus), and junglefowl (G. gallus) (Reid 1967, Lund and Chute 1974). However, the pathogenicity of H. meleagridis infection varies widely among species. Ring-necked pheasants, chickens, and junglefowl are readily infected but rarely experience morbidity or death (Lund 1967; Reid 1967; Lund and Chute 1970; 1972a,b; 1974). Wild or domestic turkeys, ruffed grouse, chukar partridge, and pea-