Reciprocal Responses of Eight Species of Galliform Birds and Three Parasites: Heterakis gallinarum, Histomonas meleagridis, and Parahistomonas wenrichi

Abstract

Embryonated eggs of Heterakis gallinarum from chickens and turkeys, carrying both Histomonas meleagridis of relatively low virulence and Parahistomonas wenrichi, were fed to 8 species of galliform birds. Heterakis developed best in young ring-necked pheasants, with young guinea fowl next best, and then young New Hampshire chickens. No mature heterakids were recovered from young chukar partridges and young turkeys or mature Japanese quail and bobwhites. In year-old Hungarian partridges a few female heterakids matured, but yielded only 8 embryonated eggs per 100, such eggs given. Histomonas meleagridis was detected in only 1 of 8 (12%) of each of the following: mature Japanese quail, bobwhites, Hungarian partridges and ring-necked pheasants, and infections were of short duration. Fifty percent of the guinea fowl and chickens, 62% of the turkeys, and 88% of the chukar partridges became infected. There was no mortality. Only the pheasants and chickens produced worms with eggs that transmitted Histomonas to susceptible turkey poults. P. wenrichi appeared in only guinea fowl, chickens, pheasants and turkeys, and usually only when Histomonas was absent or no longer in the tissues. During the past 18 years, more than 40 experiments conducted at this Laboratory have compared the responses of various species of galliform birds to one or more of the parasites associated with histomonad infections: Histomonas meleagridis (Smith, 1895) Tyzzer, 1920; Heterakis gallinarum (Schrank, 1788) Madsen, 1949; and Parahistomonas wenrichi (Lund, 1963) Honigberg and Kuldova, 1969. These comparisons, made with hosts given the same inoculum, usually included the responses of 5to 8-week-old New Hampshire chickens and Beltsville Small White turkeys (Lund and Ellis, 1967; Lund, 1967b; Lund and Chute, 1970, 1971a, b, 1972). Almost always, the size of the infective dose was governed by knowledge of the influence of three factors: the strain of parasite to be used, its adaptation to a particular host species (Lund et al., 1970), and the host species to be inoculated; this knowledge was obtained by pretesting the infective material. However, all three parasites were not studied in each experiment, and the influencing factors mentioned above were not uniform throughout. The present study employed for the first time the same inoculum for gallinaceous birds of eight species, with uniform methods throughout for studying responses of all eight hosts Received for publication 3 March 1972. and all three parasites, including the ability f the parasites to perpetuate their kind. MATERIALS AND METHODS