I have a mid-upper 20's mare that was underweight over summer, I had her teeth floated and was giving her 6lbs Purina Senior along with a fat supplement. Plus she is on turnout 24/7 and gets free choice hay 24/7 also. She is missing some teeth so can't chew hay that great but was doing great and gaining weight up until about 2 weeks ago. She started not eating her grain. I thought maybe Purina switched up their feed so I tried Nutrena SafeChoice Senior and she wouldn't touch that either. My step-dad gave her some cracked corn which she ate once and that was it, wouldn't touch it either. So I had some UlcerGuard and gave her 2 doses for a few days and gave her some sweet feed. After the first few days she was eating all the sweet feed up, so I did some research and bought a bag of Triple Crown Senior, she was eating that all up too, but now today she was back at only nibbling on it again. She has lost some weight in the past 2 weeks from not eating all her senior feed. I have her blanketed for the winter too. Should I treat her for ulcers? The UlcerGuard seemed to have helped her and she was eating again after having it for a few days. Or could it be something else?