This is a 1.5 year old English orpington. She started this today. She started breathing rapidly, no rattle, no snot, no eye swelling or bubbles. No other sick chickens. Her vent looks fine other than looking dirty. She was given a bath about a month ago and I checked her backside 2 weeks later and she was still very clean. Tonight she has white and clear streaked down the feathers below her vent and from the rib cage to the vent seems rather warm and swollen. It looks like she laid an egg today as I only have 4 chocolate orpingtons and there was 3 eggs and 1 hen is broody. She is lethargic but has eaten some and was drinking water like nothing was wrong.