Hypertrophic Pyloric Gastropathy

Hypertrophic pyloric gastropathy describes a thickening of the pylorus—the muscular ring that controls the passage of food from the stomach into the small intestine. When this tissue becomes thickened, the opening can narrow, and the normal flow of digested material may be slowed or partially obstructed. This tends to occur more often in certain small breeds, and signs often develop gradually over weeks to months. Owners typically notice vomiting that occurs some hours after eating, often containing undigested or partially digested food. The vomiting may be intermittent at first, and appetite can remain normal or even increase in the early stages. Weight loss or a failure to maintain body condition often develops over time as less food is able to pass through into the intestine. This page explores the patterns that may be observed, the mechanisms that can lead to pyloric thickening, the investigations used to assess the stomach and pylorus, and the range of approaches—both medical and surgical—that may be considered depending on the individual case.