Ultrasonographic Features of Gastropathy in Dogs with Acute Kidney Injury and Acute-on-Chronic Kidney Injury.

Despite the frequent gastrointestinal involvement, no studies have described the ultrasonographic appearance of the stomach in dogs with acute kidney injury (AKI) or acute-on-chronic kidney disease (ACKD). This retrospective study aimed to characterize the ultrasonographic features of gastropathy in such patients. Dogs diagnosed with AKI or ACKD and showing gastric abnormalities on ultrasound between January 2014 and January 2024 were included. A total of 113 dogs met the inclusion criteria. Gastric wall thickening was observed in all cases. Mucosal and/or submucosal abnormalities were present in 86.7% of dogs. Mucosal changes alone were found in 54.9%, including hyperechoic band or stripe and diffusely increased echogenicity, suggestive of possible mucosal mineralization. The most common mucosal finding was a hyperechoic band (48.4%), associated with higher calcium-phosphorus product levels. Submucosal changes alone were seen in 20.3% of dogs, typically as thickening with decreased echogenicity, consistent with possible submucosal edema. Both mucosal and submucosal abnormalities were present in 11.5% of cases. Mucosal changes were more frequent in ACKD, while submucosal alterations were more common in AKI. This study provides the first detailed description of gastric ultrasonographic features in dogs with AKI and ACKD.