I have a 22 year old QH mare that I recently moved to a new boarding stable. Yesterday I noticed a large, hard lump on her pectoral muscle in between her front legs, but to the right. It didn't seem hot. There is a scrape on it but it's healed, just the hair hasn't grown back. There is a possibility she has been kicked, since she has been with new horses, or she may have ran into a fence, but no one saw an injury happen. I'm not sure if this is related or not, but she had a bad summer last summer and had an impact type colic. After she coliced she lost weight and had an allergic type reaction to the flies. She maintained her regular appetite through all of this though and since then she has gained some weight and is no longer itchy and her coat is looking much better. I've been worming her with ivermectin. Before she coliced she was an extremely healthy horse and an easy keeper and never had a problem with flies. I'm wondering if this is a hematoma or something more serious.