Case description: A 5-month-old 1.9-kg (4.2-lb) spayed female Siamese cat was evaluated because of a history of decreased appetite, regurgitation, vomiting, and lack of weight gain.
Clinical findings: Radiographic findings included a fluid- and gas-distended stomach with a small accumulation of mineral opacities. Ultrasonographic examination confirmed severe fluid distention of the stomach with multiple hyperechoic structures present and revealed protrusion of the thickened pylorus into the gastric lumen, with normal pylorogastric serosal continuity. Endoscopy of the upper gastrointestinal tract revealed an abnormally shortened pyloric antrum and stenotic pyloric outflow orifice. Pyloric stenosis resulting in pyloric outflow obstruction was diagnosed.
Treatment and outcome: A pylorectomy with end-to-end gastroduodenostomy (Billroth I procedure) was successfully performed, and a temporary gastrostomy tube was placed. Six days after surgery, the cat was eating and drinking normally, with the tube only used for administration of medications. The gastrostomy tube was removed 12 days after surgery. Results of follow-up examination by the referring veterinarian 3 weeks after surgery were normal. Occasional vomiting approximately 2 months after surgery was managed medically. Fifteen months after surgery, the owners reported that the cat seemed completely normal in appearance and behavior.
Clinical relevance: Pyloric stenosis should be considered a differential diagnosis for young cats with pyloric outflow obstruction. The cat of this report was treated successfully with a Billroth I procedure. Histologic examination and immunohistochemical analysis of the excised tissue showed the stenosis to be associated with hypertrophy of the tunica muscularis.