I have 4 hens and this girl is the only one with missing feathers.
She has not laid for several days.
I looked and did not see any bugs.
I don't think its the other girls as she is number one Hen.
Thanks for the reply,
I have given her some ground up Oyster Shells and Tums in some yogurt this morning I was planning checking her vent for an obstruction (egg and hard droppings) when I got home from work, however she laid and egg today.
She has not been acting any differently.
Hopefully, the swelling has gone down since she laid the egg. If the swelling was not due to an egg or hard droppings, she may have something else wrong, such as a tumor or ascites (fluid collection in the lower abdomen.) Ascites can occur from heart failure especially in meat chickens from their rapid growth, but also can occur from infection, egg yolk peritonitis, and liver failure. The fluid can be drained off occasionally to relieve pain and pressure on breathing. Here is a little about ascites to read: