One of my older hens being four or five years old keeps getting a swolen abdomen I think its egg peritonitis. This the third time it has happened and its extremely frustrating with the repetitive return. The first time she came down with this she nearly died but I was able to revive her by force feeding her water, food, and antibiotics. when she comes down with this she sits in the coop all day and walks at a higher angle than normall. After a couple of weeks of antibiotics she gets better and the swelling goes down and she is the only one with this problem. When she gets better she normally stays that way until a month or so then it returns. Could it be genetics? She is a Amberlink chicken. Any advice would be appreciated because I dont want to see her keep getting this way.