Background Ultrasonographic gastrointestinal wall changes in dogs with acute pancreatitis (AP) are not well characterized in the literature. No detailed studies have described their prevalence, characteristics, distribution, or clinical relevance. Hypothesis/Objectives Describe the prevalence of ultrasonographic gastrointestinal wall changes in a population of dogs with AP and evaluate for associations between the presence of gastrointestinal wall changes and clinical or clinicopathological variables. Animals Referral population of 66 client‐owned dogs with AP. Methods Retrospective search of clinical records to identify dogs with AP. Clinical variables, clinicopathological variables and ultrasonographic findings were reported using descriptive statistics. A binary logistic regression model was used to evaluate for associations between the presence of gastrointestinal wall changes and clinical or clinicopathological variables. Results Sixty‐six dogs were included. Forty‐seven percent of dogs (95% confidence interval [CI], 35.0%‐59.0%; n = 31) with AP had ultrasonographic gastrointestinal wall changes. Gastrointestinal wall changes were most common in the duodenum and identified in 71% (n = 22) of affected dogs. Of dogs with gastrointestinal wall changes, 74.2% (n = 23) had wall thickening, 61.3% (n = 19) had abnormal wall layering, and 35.5% (n = 11) had wall corrugation. In the multivariable model, only heart rate remained an independent predictor of ultrasonographic gastrointestinal wall changes (P = .02). Conclusions and Clinical Importance Ultrasonographic gastrointestinal wall changes in this population of dogs with AP were common. Increased heart rate was the only independent predictor of gastrointestinal wall changes, which might imply more severe disease. Additional studies are required to elucidate whether ultrasonographic gastrointestinal wall changes reflect disease severity in AP.