The Occurrence of Gizzard Worms in Canada Geese

Abstract

The roundworm parasite, genus Amidostomum, occurs as an adult under the horny lining of the avian gizzard. It was originally described from domestic geese in Germany by Zeder in 1800, and has since been reported as a cause of extensive losses among these birds in Europe. Typical symptoms are loss of appetite, anemia, and emaciation. This syndrome could result from the combined effects of loss of blood, toxic effect of parasite upon host, and digestive disturbances brought about by improper functioning of the diseased gizzard. The clinical pathology of the infection has been discussed by Bunyea and Creech (1926). The first North American record of an outbreak involving A. anseris in domestic geese came from New York State (Cram 1925, 1926). Since then outbreaks have been reported from Washington (Jerstad, 1936, and Adler and Moore, 1948), from Maryland (Farr and Wehr, 1952), and from Canada (Oliver, 1952, and McCraw, 1952). Gizzard worms were first reported from wild Canada geese (Branta canadensis) by O'Roke (1928) who recorded Amidostomum sp. from this host, and from several other species of native geese and ducks taken in California during the hunting season. In the summer of 1926 Wickware (1930, 1941) reported the occurrence of Amidostomum anseris in large numbers in several Canada goose goslings which died at a game sanctuary in western Ontario. Light infections with A. anseris were found by Jerstad (1937) in two Canada geese and a lesser Canada goose (Branta canadensis leucopareia) collected in the state of Washington. Wehr (1933) reported A. spatulatum from a Canada goose taken in New York State. Since 1948, we have had an opportunity to examine gizzards of a large s ries of Canada geese coming from several localities in the United States, but mostly from birds wintering along the coast of North Carolina. Part of the findings of these examinations have been published in a paper dealing with occurrence of Amidostomum anseris