Remission of diabetes mellitus induced by prednisolone in combination with cyclosporine toxicity in a cat

A 6-year-old spayed female domestic short-hair cat was presented for primary complaints of anorexia and lethargy. The cat was being treated with cyclosporine (25 mg/cat, PO q24h) and prednisolone (1 mg/kg, PO q12h) for feline hypersensitivity dermatitis and inflammatory bowel disease for 1 year, wherein prednisolone was withdrawn 2 weeks prior to presentation. At presentation, dehydration, hyperglycaemia, ketonaemia, increased fructosamine, glucosuria, ketonuria and metabolic acidosis were observed. The cat was diagnosed with diabetic ketoacidosis (DKA). Immediate treatments with insulin continuous-rate infusion and intravenous fluid therapy were initiated. A serum cyclosporine concentration was >2100 ng/mL, indicating cyclosporine toxicity. Cyclosporine was discontinued immediately. The cat's acidosis and ketonaemia were resolved within a week, allowing a switch from insulin continuous-rate infusion to subcutaneous glargine (1 IU/cat), which was eventually discontinued due to persistent normoglycaemia 12 days after initial presentation. Hyperglycaemia was not observed for 28 days thereafter without insulin, indicating remission of diabetes mellitus. This report suggests that using prednisolone, particularly immune suppressive doses, could be problematic in cats receiving long-term cyclosporine therapy. Additionally, diabetic cats receiving immune-suppressive agents can possibly achieve diabetic remission after surviving DKA through regular monitoring of blood glucose concentration, elimination of prednisolone and intensive blood glucose management.