Sussex bulge rear end

[MarketGardener]

Few years ago I got 10 sussex chickens 1had a bulge on the rear really big and soft didn’t appear Poorly just u slightly could just notice her feathers lower than the rest , gave her to a chicken vet to keep ,
Now my girls I kept have been flawless , there fine healthy flighty eating mating the works ,one is sat on eggs day 13 she is a good mum,

We noticed her sister when cleaning looked lower on the ass like a duck , or a very feathery mum bum as we call it lol (the ones that wana brood seem bushier)

I caught her and felt that chicks ass, where it normaly feels flat she has like a fat sack under the vent behind the legs right where the fat sits when ya feed chickens up for harvest if that makes sence thee fat pad bit

Feels soft no discomfort in her at all she couldn’t wait to run away,
What is this ? Sussex breed problem? Hernia? I don’t know lol is she fat?
Chicken on the right see how her ass looks bigger than the other

 

[Eggcessive]

Some hens may have extra fat there, but fluid from water belly/ascites can be common. If it feels firm, I would look more at it being internal laying/salpingitis or a tumor. What do her poops look like? Are the urates in her poop white or yellow?

 

[MarketGardener]

Some hens may have extra fat there, but fluid from water belly/ascites can be common. If it feels firm, I would look more at it being internal laying/salpingitis or a tumor. What do her poops look like? Are the urates in her poop white or yellow?

Poops all the normal rage colour, it’s soft as like can barely grab it comparable to I’d say trying to grab flour or fine seeds or air in a bag