Fourteen cats were given immunosuppressive doses of either prednisolone (4·4 mg/kg/day) or dexamethasone (0·55 mg/kg/day) for 56 days. Complete blood counts, serum biochemistry profiles and urinalyses were performed on days 0 and 56, and liver biopsies were taken laparoscopically on day 56, because of evidence of hepatic disease on the serum biochemistry profiles. There were significant increases in the cats' mean white blood cell counts, neutrophil counts and monocyte counts, and significant decreases in their mean lymphocyte counts and eosinophil counts. There were consistent increases in the serum concentrations of albumin, glucose, triglycerides and cholesterol. Glycogen deposition, consistent with a steroid hepatopathy, was present to varying degrees in all the liver biopsies. One of the cats developed adverse clinical signs including anorexia, icterus, pruritus and medial curling of the pinnae, some of which were suspected to be related to the glucocorticoid therapy.