ABSTRACT:The aim of this study was to evaluate the effect of Budesonide on the hypothalamic-pituitary-adrenal (HPA) axis in dogs with inflammatory bowel disease. The effect of orally administered Budesonide (Entocort) on the HPA axis was analysed in 21 dogs with inflammatory bowel disease. Biochemical analyses were carried out to evaluate the activity levels of alanine aminotransferase, asparagine aminotransferase, alkaline phosphatase, cortisol and endogenous adrenocorticotropic hormone. Urine samples were collected from each patient before the study and after 30 days of the experiment to determine the composition and the physical and chemical properties of urine sediments. Considerably lower serum concentrations of cortisol and endogenous adrenocorticotropic hormone were observed after 30 days of treatment. A significant increase in alkaline phosphatase levels was noted on Day 30. In the studied dogs, the drop in HPA axis activity was correlated with side effects associated with the administered glucocorticosteroid (polyuria, polydipsia). In conclusion, we have shown that oral administration of Budesonide to dogs diagnosed with inflammatory bowel disease significantly suppressed the activity of the HPA axis.Keywords: glucocorticosteroids; IBD treatment; eACTH concentration; side effects; HPA axis List of abbreviations ACTH = adrenocorticotropic hormone, ALKP = alkaline phosphatase, ALT = alanine aminotransferase, AST = asparagine aminotransferase, CD = Crohn's disease, CIBDAI = canine inflammatory bowel disease activity index, CORT = cortisol, eACTH = endogenous adrenocorticotropic hormone, GC = glucocorticosteroids, HPA = hypothalamic-pituitary-adrenal axis, HUC = histiocytic ulcerative colitis, IBD = inflammatory bowel disease, SG = urinary specific gravity, UC = ulcerative colitis