I think he's about a week old and probably a sebastopol. He is alert, friendly and eating and drinking. Not sure exactly when the lump started, I noticed it yesterday but it might have been there the whole time. It doesn't seem to hurt him if I touch it. Hasn't been hurt, but his breathing sounds mucous-ey. Poop looks fine, as far as I can tell, but I think he had two runny ones earlier. The original owner gave me antibiotics because he thought he had a cold, but I don't think it's helped. He is living in a cardboard box with plenty of food and water with towels on the bottom and a heat lamp. Any help/ ideas greatly appreciated.