I was a bit reluctant to write anything, because I really don't know who did your duck. I thought I might be able to write something to help you find out, however. If I am looking at the picture right, the duck appears to be holding its wings down at its side. Fratelli Toso did several similar birds, but the ones that have wings like your duck tend to have the wings up above the back. Several of the Seguso pieces with this type of wing have the wings held down by the side.
Many Italian and other companies made cased birds. Your duck does look Italian to me, but I cannot be sure of the company. The only thing I can say is probably not Fratelli Toso and maybe Seguso. I hope someone else can add a little more.