Hen with swollen abdomen
It sounds a s if she might have an internal laying problem. It can also affect the liver causing ascites or fluid in the lower belly making it tight and causing shortness of breath. Runny droppings, a lack of appetite, and penguin walk or wanting to sit can be other symptoms. Each case is different, and there may not be much that you can do, but some people use antibiotics or seek vet care.