Evaluation of Treatment with a Combination of Mycophenolate Mofetil and Prednisolone in Dogs with Meningoencephalomyelitis of Unknown Etiology: a retrospective study of 86 cases (2009-2017)

Abstract Background Combination therapy with glucocorticoids and adjunctive immunomodulating drugs has been generally accepted as a standard treatment regimen for meningoencephalomyelitis of unknown etiology (MUE). Mycophenolate mofetil (MMF) has been considered a comparable alternative option to other previously reported immunosuppressive agents. We hypothesized that treatment with MMF as an adjunctive agent along with glucocorticoids would be effective in dogs with MUE and safer than other immunosuppressive protocols. Eighty-six dogs with MUE were included. The medical records of dogs with MUE treated with prednisolone and MMF were retrospectively evaluated to determine the response, survival time, and treatment-related adverse effects. A partial or complete response (CR) was recorded for 75 dogs. Results The overall median survival time from the initiation of treatment was 558 days. Dogs that showed CR with no relapse over the treatment period had significantly longer median survival times. A significantly higher mortality hazard ratio of 4.546 was recorded in dogs that failed to achieve CR. The interval between the onset of clinical signs and the presentation was not significantly associated with CR, relapse rate, and survival time. Adverse effects included gastrointestinal upsets in 26 dogs, sporadic infections in 17 dogs, and pancreatitis in seven dogs. Conclusions The results suggest that adjunctive MMF treatment for MUE is safe and comparable to other immunosuppressive protocols. The treatment should focus on the achievement of CR and preventing relapse for successful management.