Multicentric intramuscular lipomatosis/fibromatosis in free-flying white-fronted and Canada geese.

Over a period of 9 yr, seven white-fronted geese (Anser albifrons) and one Canada goose (Branta canadensis) with multiple intramuscular mesenchymal tumors were encountered in Saskatchewan (Canada) and one similarly affected Canada goose was seen on Prince Edward Island (Canada). The tumors in these birds consisted either of adipose tissue, fibroblastic tissue, or a mixture of both types of tissues. The high prevalence of this condition in white-fronted geese suggested a genetic influence.