The effect of inflammatory bowel disease (IBD) on the density of galanin - immunoreactive (GAL-IR) nerve fibers was determined in the mucosa of canine duodenum, jejunum, and descending colon. Fiber density was evaluated by a single immunofluorescence method in biopsy specimens obtained from healthy dogs and patients with variable severity of the disease. The density of GAL-IR nerve fibers was determined by the semi-quantitative method by counting fibers in the field of view (0.l mm2). Fiber density was higher in dogs with moderate and severe IBD than in healthy animals. The results of the study suggest that GAL present in intestinal nerve fibers could play a role in the pathogenesis and development of canine IBD.