Spontaneous gastric ulcers in rodents are rare. From 6/92 thru 6/93, 30 of 43 lab bred fat sand rats died due to gastric hemorrhage/ulcerations. Ulcers were multiple, ranging from pin-point lesions to greater than 1cm and most were found in the non-keratinized stomach portion. Helicobacter species have been linked to gastritis in humans and animals. New species isolated from rodents have been linked to hepatitis. Histologic analyses are in progress to identify a possible bacterial cause for the ulcers and deaths.