So i've posted in Ducks, but nobody is replying. Yesterday one of my ducklings(week old) passed away. Today i've noticed that the other 3 are with swollen bellies. When i touched them i found that they're very hard (like full with pebbles). One of them got really bad, it only stoods under the lamp and it's not mooving. I thought it must be from the food (chicken starter) so i gave them cucumber and plenty of water. The two got better started pooping some jelly-like light pink substance. But this one is not pooping at all. It goes back as if it will poop, but nothing comes out. Please, someone help me give me some piece of advice. I am very new to ducklings (these are my fist) and i don't know what to do.