Our hard keeper turned out to have eosinophillic enteritis - and her skin was also affected with chronic lympho-eosinophillic dermatitis. The two were connected.
She came to us from Texas with some odd patches on her skin and a tendency to have "colic" symptoms... she was in foal at the time and I hoped the foal was just causing her discomfort. No meds seemed to help her. Banamine did not give her relief. The "colic" came and went. Good for a week, then a bad night. Then 2 good days. Then another bad night - during which she would often lay on her back with her front legs folded up. After that foal was weaned and she had trouble picking up weight, we had her U/Sed etc. at the equine hospital. The ultrasounds showed a section of her small intestine had thickened walls and allowed only a small bit of food to get through. She had surgery to remove the 4 feet of her small intestine that was affected, had a strict worming protocol to follow - and slowly began to blossom again - although she was always a picky eater and the skin issues occurred on and off until fall & winter. After 2 years, she was cleared to breed again - and suddenly, during her pregnancy the same symptoms began to reappear. No upside-down episodes - but everything else was the same to me. I felt it was the same thing occurring again. This time - the weight came off her as if she was melting.
The filly was weaned early at 2 months and is doing well. Another exam of the mare at the hospital showed that her entire small intestine is now affected. We brought her home as we figure she should be comfortable and with friends in the time she has left. She has probably had a low level of pain for the past few years - long before she came to us as well... so I keep her comfortable and tempt her with goodies and hand graze her on the lush lawn in the evenings. She will graze with all the enthusiasm she can muster for eating of any kind - and she has actually put on a bit of weight. If any strangers saw her, they would think she was a neglect case - at one point she had a BCS of 2. I would put her at a 3 - 3.5 now. Any progress is great!
Her eyes are bright, she seems relaxed and content for the moment. She actually bucked and ran across the pasture when she was turned out this morning! She is on steroids and they seem to be helping. Her little filly is in the next field with the other foals - and they visit through the fence to comfort each other - but neither one stresses when the other wanders off.
We are not kidding ourselves - there is no cure and her time is limited - and as soon as I see her fading or showing me she is in pain and no longer willing to go on, I will hold her as the vet sends her on her way. We are monitoring her carefully and will not let her suffer.
As I type, she is out under the pine tree in the shade, grazing side by side with her chubby BFF...