The gizzard nematode, Amidostomum anseris, has been reported frequently as the cause of losses among domestic geese in Europe. Cram's (1925) report of an outbreak in domestic geese in New York State was the first evidence of this worm in North America and since then there have been several reports of its occurrence in many parts of Canada and the United States. There have been a few cases of A. anseris reported from Canada goose (Branta anadensis) and one report of A. spatulatum from this host. The authors have reported A. anseris from goslings from Michigan and Utah. Beginning in 1948 we have had opportunity to examine the gizzards of a large series of Canada geese from several localities in the United States, mostly wintering birds from the coast of North Carolina. A. anseris was the only species identified from examination of a representative sample from our collection of gizzard worms. . A high incidence of infection with Amidostomum was observed in geese from many localities in the United States, including all the major flyways. In most cases only a small number of worms was recovered from each individual but birds from a refuge in North Carolina, which was studied intensively because of periodic winter losses, yielded significantly higher numbers of worms per bird. The mean number of worms per individual from most areas was under 15 while from this specific refuge the mean was in the seventies each of the past three years, with one bird having over 1500 specimens in its gizzard.
