I went to Slimbridge today, looking for Berwick's Swan, Whooper Swan, Pink-footed Goose, but I couldn't get close to the many that have flown in. So, I threw in some others there.
And this one does have a disease. (Fringilla papillomavirus, Warts). It seems that 1/3 of Chaffinches is likely will end up with it, both sexes. It's a terrible to have that, but, it wont kill them and doesn't restrict their usual galloping around.