I hatched four Sebright eggs under a broody hen. One died the day of, and another died three weeks later of a weird respiratory disease. Now my sole little rooster is blown up like a balloon! His whole chest is filled with air, all the way up into his neck. I didn't know what to do, so I stuck a clean pin into him and he deflated. But I've had to do that seven more times and he just keeps filling up with air! The last time I deflated him I thought I felt a little lump in his crop. I've never heard of such a thing and I'm not sure if I'm helping or hurting the little guy. His sister is a perky little chick who has none of these problems. He is 18 weeks old and is still perky too, eating and drinking and otherwise acting normal. What should I do?