Abstract
Ultrasound (USG) is a valuable diagnostic tool for evaluating the gastrointestinal tract of small animals, offering non-invasive and dynamic information. This review discusses intestinal evaluation in dogs using B-mode ultrasound and the advanced technique of contrast-enhanced ultrasound (CEUS) with microbubbles. B-mode USG allows the thickness and stratification of the intestinal wall, motility and adjacent structures such as lymph nodes and peritoneum to be examined. Reference values for intestinal wall thickness in dogs have been established based on body weight. The duodenum, jejunum and ileum can be differentiated sonographically by their location, wall stratification and relationship to other intestinal segments. Intestinal motility is assessed by counting peristaltic waves, and abnormalities indicate various diseases. CEUS uses microbubble-based contrast agents, such as sulphur hexafluoride, which remain stable in the vascular system and are eliminated by the lungs. This technique improves the perception of ultrasound echoes, making it possible to quantify tissue perfusion with parameters such as entry time, peak enhancement and exit time. In human medicine, CEUS is used to assess intestinal perfusion in conditions such as Crohn's disease and ischemia. In veterinary medicine, the technique has been used to assess duodenal perfusion in healthy dogs and those with chronic enteropathies or alimentary lymphoma. Although CEUS shows potential in differentiating dogs with chronic enteropathies from healthy controls, more research is needed to standardize the methodology, establish reference values and define clinical applications in various canine intestinal diseases. The combination of B-mode USG and CEUS provides a non-invasive assessment of intestinal morphology and function, contributing to the understanding of the pathophysiology of enteropathies in dogs.

Key words: Canine, Contrast, Ultrasound, Intestinal wall thickness, Microbubbles