One of my hens, a 3 year old Buff Orpington hen, Sansa, has been slowly going downhill and I have done research on line, I have read all the diseases and symptoms and today called our small animal vet to please see her. Have an appointment for tomorrow early afternoon. For the past few days Sansa has been weak, she walks but with a slight gimp and if she has to get out of the way of another hen, she will stumble and sometimes fall but gets back up with a slight struggle. Her feathers are unthrifty, today she was in the sun ruffled up, her comb and wattle are pale, and she does have very watery stool, when you look at her vent it leaks out though she seems to have good muscle control if you touch her there. When I checked her vent I noticed the skin around it and down on her abdomen/lower chest is a dark purple, red color, I feel nothing that would lead me to believe she is egg bound nor is she straining or has she laid since getting her 3 or so months ago. I do have her in a large kennel in the basement with fresh food, water, and hay to stand/sit/lay in, which ever she prefers and near the door so she does get light. When I called the vet and explained what was going on, one tech said it really sounds like a circulatory problem or a heart problem, that chickens can get that too. Anyone have any ideas I can look up or read about and try to figure this one out? She does try to eat but she is thin.