Hosscrazy's comment put my focus on her diet. A week prior, I had brought her in to pamper her since she was older and in her last trimester of pregnancy. While she was in descent "body weight" shape, I thought I would up her feed and put on a few pounds and started her on Calf Manna and free hay. With the insulin/glocose comment , I cut out the calf manna. Within 3/4 days, she was dry in the morning but still sweaty by days end. After 8/9 days she was dry and no more sweats. A few weeks later I mentioned this scenario to another "mini" breeder. Last fall he had purchased 5 pregnant mares and stalled them. After a week one mare got all sweaty, and like me , thought this was an abortion unfolding. He feeds corn, which would not have been in their previous diet. He stopped feeding corn and within the week his mare was not sweating. We looked had the ingredients label for the calf manna and guess what, the third item was corn. We concluded in our laymens terms that we each have a mare that is intolerant of corn or some component of the corn.
This situation is currently being discussed by the nutritionists and vets of the feed company mfg the product and should get some feedback in due course.