Cockatiel w/ swollen chest
I have a 17 yr. old cockatiel, and I have been noticing that his droppings are mostly liquid here lately. Also, I was feeling his chest earlier today and it feels like it is swollen, it is not a hard lump or anything, it actually feels spongy like. However, he acts completely normal and doesn't seem like he is in any pain or anything. What could be wrong? Could it be a tumor?