A 13 year old, Quarter Horse mare presents to the SVEC Sports Medicine service with a history of displaying intermittent mild signs of colic for the past 6 months (July – December). The signs of colic include inappentence, flank watching and pawing. The symptoms are alleviated with an appropriate dose of Flunixin Paste orally. Her manure is loose at times and she does urinate frequently. She seems more irritable when ridden and a bit more aggressive towards her pasture mates. The referring veterinarian performed a rectal exam and found a large hard mass in the right mid abdominal area.
What is your diagnosis and next steps/treatments?