Over the last six months I have had several issues with sour crop in my flock. Through a lot of trial and error I have discovered a Method of treatment which has worked for me on no less thn six occasions with brilliant results. Sour crop can be worrying your girl goes off her her food and becomes listless with a crop that feels like a water balloon and stinky breath like you wouldn't believe, not very nice for her or you. In the first instance you must isolate her from your other girls so you can keep an eye on her and stop the others from bullying her. Secondly, carefully empty her crop by holding her upside down an massaging the crop (YouTube has demonstrations of how to do this) Finally, add kefir milk to her feed for the next 2 weeks, after which time she'll be back to her old self. This treatment has worked like a dream for me, there's been no vets bills, haven't had to use antibiotics and most importantly I haven't had one fatality. I hope this advise is of use to anyone who's girls are ill with sour crop.