An outbreak of schistosomiasis in Atlantic brant geese, Branta bernicla hrota.

A heavy infection with schistosomes of the genera Trichobilharzia and Dendritobil- harzia was considered the cause of 90% mortality in a group of 40 wild-caught Atlantic brant geese (Branta bernicla hrota) that were maintained in captivity on a fresh-water pond in Aurora, Ontario. Numerous adult worms and eggs were disseminated in many organs throughout the body of all birds examined. The main pathological findings, attributed to both eggs and adults, included emaciation, thrombosis of the caudal mesenteric vein and its branches, fibrinohemorrhagic colitis, and in some birds, heptomegaly. Translocation of brant geese from their natural marine environ- ment to a fresh-water pond may have caused them to be exposed to parasites which they would not normally encounter.