I've been pretty fortunate, I've only seen 1 bird with that. Are they like maggots? If you dig 'em out are they moving? You could save them for ice fishing I only bring home about 8 birds a year though.
I had a bird like that in Oregon a couple of years ago. The round, hard fat nodules look just like maggots. I showed it to my wife, who is a nurse. She said, "Maybe that image and a reminder that you have already had a heart attack will make you look again at the Mediteranian Diet."
Hutch, I thought you liked ducks over rice. What's wrong with nature combining the two for you? I've never shot one, but it seems when they come its in multiples. I've had buddies that shoot 2 or 3 in a shoot, which makes sense given the origin.