Finch has extremely swollen abdomen

[finchman]

I noticed today that one of my society finches abdomen is extremely swollen. When touched it feels almost like a balloon. I thought at first it might be a ruptured air sac but there isn't any swelling in the upper part of its body. It seems to be acting normally although it must be in a great deal of discomfort. He/she has had Ronex recently as a routine treatment as well as been wormed. I have Sulmet, and Amnitox on hand but I don't know if I can give that to it because it is currently part of a trio fostering a clutch of gouldians. I can't see how I wouldn't have noticed it for any prolonged period (tumor?) but I suppose it's possible. I'm at a total loss. The rest of the flock seems healthy and happy including the chicks. Has anyone seen anything like this before?

[cindy]

is this a hen? If a hen, an egg may have broken inside, it creates bacteria.... the belly continues to expand with a brown dark fluid, it can be drained by a vet and Baytril given but usually the swelling/fluid comes back.

Can you turn the bird around and show the underside, wet the feathers and push the feathers back off the lower belly all the way to the sides.