I have some problem in my loft. One pair of fantail doves had a single chick. This chick did well until about half grown, then it started to loose weight and get weak, and it stopped begging it parents for food. It tried to feed it myself, but nothing would go into the poor thing, and it got worse and I had to put it to sleep. Now another pair of a different breed raised a single squab, it grew well and was very healthy, then it flew the nest, still did well. But today it was very lethargic, and I picked it up, and it was very thin and as I lifted it up, clear liquid comes from its beak. I can feel no food in the crop (like the fantail squab), and it keeps dribbling this liquid from its beak. Its poop is light green and frothy. Again it will not eat anything, and shown no signs of interest in food. It is going down hill fast and I fear it will be dead in the morning. What diseases can cause this to happen? All the adult pigeons are very fat and healthy. I can not get them tested for anything... I live in remote rural Thailand. Should I cull my birds and start again? Or is this just some bad luck? Can you think of any diseases that kill off the older squabs, but not the parents? Thank you for any information.