Today I have got a sick feral. It is a fully grown-up. He has got a lump on his neck and looks terribly swollen. When I feel the lump, it is semi solid and liquid. The pigeon seems suffering as the lump is forcing his neck to elevate at an awkward angle, not at a normal and comfortable position of a pigeon neck. His head is bobbing frequently to and fro. Losing flight ability. Droppings are sharp green with some translucent gel. The green and translucent fluid are not mixed. They are apart. Any advice would be appreciated. And I would like to know if it carries transmissible diseases since I have to decide whether to separate it from my other rescues.