So I have a 6 month old rooster (cornish x hen × production red roo), on whom I found a tumor (?) when I picked him up this evening. I don't recall anything feeling unusual when I picked him up about a month ago, but it seems pretty big. It's firm, but there's fluid build up around the edges. His brother just went lame about a week ago, so I'm starting to worry we have marek's. But I have 20 chickens all together, and no one else seems to be having any trouble. Any thoughts?