A 10 year old warmblood gelding presented to Cornell University’s Equine and Farm Animal Hospital on June 15th, 2009 with a history of a fever of unknown origin, recent weight loss and inappetance. Upon presentation, the gelding was quiet and alert, tachycardic, had a poor body condition score (3/9) with muscle wasting, and ventral and hindlimb edema. Other history includes twelve months of stall rest for a hindlimb lameness and previous treatment with phenylbutazone at an unknown dose and frequency. Gastroscopy was performed and it was noted that the stomach failed to empty after several fasting attempts. The gelding was diagnosed with delayed gastric emptying, and at the third attempt at gastroscopy, a large glandular ulcer was found. This report describes a complicated and interesting case of presumptive non-steroidal anti-inflammatory drug (NSAID) induced glandular gastric ulceration with subsequent gastric perforation, abscessation, peritonitis, and ganglioneuritis which resulted in delayed gastric emptying and small intestinal hypomotility.