A 14 week old female boxer, presented for a chief complaint of chronic regurgitation since weaning. Physical examination revealed the patient to be thin with a body condition score of 3/9. Complete blood count, blood chemistry panel, and orthogonal view thoracic radiographs were unremarkable. Fluoroscopic esophagram was unremarkable. Upper gastrointestinal fluoroscopy was positive for pyloric outflow obstruction. Ultrasound of the pylorus also supported the diagnosis of pyloric stenosis. The patient was treated surgically with the Billroth I procedure (pylorectomy with gastroduodenostomy). Surgical biopsy of the lesion was described as benign hypertrophic pyloric gastropathy, confirming the diagnosis of pyloric stenosis. The patient ceased to regurgitate after discharge. Two months postoperatively, the patient was still thin but gaining weight consistently and in good health. The congenital form of pyloric stenosis, while rare, is over-represented in brachycephalic breeds, but the mode of inheritance is still unknown. Successful surgical correction has a good prognosis, as illustrated by this case.