We've got a young hen with similar issues who just ended a 20 day course of antibiotics. She is back with the flock and foraging like the rest of them, but still has a swollen abdomen and tires easily. I have not tried draining her. I'd find that difficult but have gained the confidence to give it a try based on the really helpful descriptions on backyard chicken. Our young hen had the penguin walk when we started all this, and now she seems a little less swollen and she holds her tail more normally. I'm going to start supplementing with milk thistle based on some readings in backyard chicken. She did not seem egg bound--the vet saw no indication of it and she started laying eggs again during the second course of antibiotics--so I'm thinking we're dealing with fluid in the abdomen from either heart disease, liver disease, or possibly reproductive tumor. We'll try the milk thistle and hope that the cause is a liver problem and the milk thistle helps her fight it a bit better. I'm keeping the eggs she has laid recently and feeding them back to her figuring the antibiotics in them won't do her any harm seems how she just finished a 20 day course. The nutrition in the eggs should do her good. I'm not very worried about restoring her gut microbes from the antibiotics because our hens have time for free range foraging every day. Not like us humans that eat sterile food all the time. I suspect there really isn't much need to feed chickens yogurt if they do get opportunities to forage in wild places (our hens have access to a vegetable garden, woods, and untreated lawn/meadow). It has been so helpful and reassuring to read these posts on hens with swollen abdomens. I'm feeling much better about my ability to make decisions that may help our poor gal.