A Consideration on the Relationship between Worm Age and Mortality of Setaria marshalli Recovered from the Peritoneal Cavity of Calves Born in Tottori Prefecture, Japan

摘要

References(11) Cited-By(1) Eight calves born in November-December of 1992 were necropsied at the ages of 29-230 days in an attempt to estimate the life span of Setaria marshalli in Japan. Worm ages were estimated on the base of active season for mosquitoes. Thirty worms estimated 4-9 months old recovered from 4 calves were all alive in the peritoneal cavity. Thirty-five out of 50 worms estimated 7-13 months old were dead with being entrapped by fibrin on the peritoneum. It is speculated that this is a normal fate of this parasite at the end of its life, and therefore, the life span of S.marshalli would be approximately one year after prenatal infection.