Background Contrast‐enhanced ultrasonography (CEUS) can be used to evaluate intestinal perfusion in healthy dogs. It is helpful for diagnosing and monitoring inflammatory bowel disease in humans and could be useful for dogs with chronic intestinal diseases. Objectives To examine duodenal perfusion in dogs with chronic inflammatory enteropathy (CIE) and intestinal lymphoma. Animals Client‐owned dogs with CIE (n = 26) or intestinal lymphoma (n = 7) and dogs with gastrointestinal signs but histopathologically normal duodenum (controls, n = 14). Methods In this cross‐sectional study, dogs with CIE were classified into remission (n = 16) and symptomatic (n = 10) groups based on clinical scores determined at the time of CEUS. The duodenum was scanned after IV injection of Sonazoid® (0.01 mL/kg). CEUS‐derived perfusion parameters, including time‐to‐peak, peak intensity (PI), area under the curve (AUC), and wash‐in and wash‐out rates were evaluated. Results The PI was significantly higher in the symptomatic CIE group (median (range); 105.4 (89.3‐128.8) MPV) than in the control group (89.9 (68.5‐112.2) MPV). The AUC was significantly higher in the symptomatic CIE group (4847.9 (3824.3‐8462.8) MPV.sec) than in the control (3448.9 (1559.5‐4736.9) MPV.sec) and remission CIE (3862.3 (2094.5‐6899.0) MPV.sec) groups. The PI and clinical score were positively correlated in the CIE group. No significant differences in perfusion parameters were detected between the lymphoma and CIE groups or the lymphoma and control groups. Conclusions and Clinical Importance The PI and AUC can detect duodenal inflammation and hence are potentially useful for excluding a diagnosis of CIE.

Contrast-enhanced ultrasonography (CEUS) with microbubbles as a contrast agent allows the visualization and quantification of tissue perfusion. The assessment of canine intestinal perfusion by quantitative CEUS may provide valuable information for diagnosing and monitoring chronic intestinal disorders. This study aimed to assess the repeatability (intraday variability) and reproducibility (interday variability) of quantitative duodenal CEUS in healthy dogs. Six healthy beagles underwent CEUS three times within one day (4-hr intervals) and on two different days (1-week interval). All dogs were sedated with a combination of butorphanol (0.2 mg/kg) and midazolam (0.1 mg/kg) prior to CEUS. The contrast agent (Sonazoid®) was administered using the intravenous bolus method (0.01 ml/kg) for imaging of the duodenum. Time-intensity curves (TIC) were created by drawing multiple regions of interest (ROIs) in the duodenal mucosa, and perfusion parameters, including the time-to-peak (TTP), peak intensity (PI), area under the curve (AUC), and wash-in and wash-out rates (WiR and WoR, respectively), were generated. Intraday and interday coefficients of variation (CVs) for TTP, PI, AUC, WiR and WoR were <25% (range, 2.27–23.41%), which indicated that CEUS was feasible for assessing duodenal perfusion in healthy sedated dogs. A further study of CEUS in dogs with chronic intestinal disorders is necessary to evaluate its clinical applicability.