Hey guys so i have a black and white chicken that i think is a Plymouth rock and i think she is sick. Her companion hen is a Rhode Island red and a few months ago the red had an extreme increase in weight, had trouble passing poo (which would often end up stuck to her rump feathers, she also drsnk drank a lot of water and sometime had liquid poo. I tried putting about a droplet of anti biotics and tried isolating her from the other 2 hens and she seemed to get better. Now the Plymouth rock (who used to be our most plump hen) has lost a ridiculous amount of weight, has a lack of activity and is constantly sleepy or sleeping. She drinks water but doesn't eat a lot and she is constantly having wet poo and has a dirty butt. Also she is very unstable, if i pick her up and put her down she will slowly fall to her butt and i saw her sitting like that in her butt. Finally she has a lack of vibrant color on her comb or face and hasn't started laying eggs while or red has. Guys please help me diagnose the problem and fix it.