Gastric retention associated with a pyloric mass in two horses.

Partial pyloric obstruction causing gastric retention is described in 2 young female horses. Gastric retention was confirmed by contrast radiography of the upper gastrointestinal tract. In both horses a large mass was palpated in the wall of the pyloric antrum at exploratory laparotomy. Post-mortem examination of the first case confirmed that this mass was associated with chronic gastric ulceration. Gastric ulceration was not confirmed in the second case but this horse recovered after the pylorus and duodenum were bypassed by gastro-jejunostomy.