She's still inside and is not eating. It appears as if her crop has swollen with air. I've 'burped' her several times and tried massaging the crop to see if there's any obstruction. There's just nothing in there at all. Her stools still look normal as well. As soon as I burp her, the crop just seems to swell back up with air in a matter of minutes. I've tried giving her sugar free yogurt and water with ACV added. Please advise.