An 8-year-old female spayed Pug presented to the Cornell Animal Hospital Medicine service with a one-week history of anorexia, decreased frequency of defecation and generalized abdominal pain. Physical examination revealed no abnormalities other than a tense and painful abdomen. A diagnostic work-up was performed including CBC, chemistry panel, abdominal radiographs, abdominal ultrasound and fine needle aspirate (FNA) of the mesenteric fat with subsequent cytology examination. Imaging and FNA findings were consistent with a mesenteric steatitis. Mesenteric pannniculitis, an uncommon but similar inflammatory disorder of the fatty tissue in the bowel mesentery of humans, is well documented in literature. This paper discusses the clinical, laboratory, cytologic, histopathologic and imaging diagnostic findings associated with idiopathic mesenteric steatitis in the canine patient, while briefly contrasting it to mesenteric panniculitis in humans.