Endoscopic assessment of presumed acquired pyloric narrowing in cats: A retrospective study of 27 cases.

Acquired pyloric narrowing is a rare and poorly-documented condition in cats, but the endoscopic appearance of pyloric narrowing has never previously been reported. The objectives of this study were to describe the clinical, endoscopic and histological features in cats with gastrointestinal signs where the pylorus could not be passed during endoscopy, and to compare these data with a control group. Medical files of cats that underwent upper GI endoscopy by the same operator between 2006 and 2015 were reviewed. Cats for which the pylorus could not be passed were assigned to the case group, whilst those with an easily-passable pylorus were assigned to the control group. The case group comprised 27 cats and control group comprised 35 cats. Median age and weight were not different between groups, but there were more Siamese cats in the case group (6/27) compared with the control group (1/35; P = 0.04). Chronic vomiting was the main clinical sign in both groups, but the vomitus was more likely to contain food in case group (23/25) than in cats in control group (17/30; P < 0.01). Endoscopic findings confirmed gastric inflammation in both groups, whilst histological findings revealed similar lymphoplasmacytic infiltration of the gastric mucosa and the duodenum in most cases, neoplastic features being infrequent. Acquired pyloric narrowing is probably an underdiagnosed condition in adult cats. A possible association between pyloric narrowing and gastrointestinal inflammatory disease requires further study but, for now, it is recommended that multiple gastric, pyloric, and duodenal biopsies be acquired during the endoscopy.