A retrospective evaluation of the steroid sparing effects of oral mycophenolate mofetil (MMF) as an adjunct immunosuppressant for the treatment of canine pemphigus foliaceus.

Abstract

Oral mycophenolate mofetil (MMF) currently is considered a low-risk steroid-sparing therapeutic option for the management of canine pemphigus foliaceus (PF). This retrospective study evaluates the therapeutic outcomes of dogs with PF treated with the combination of oral MMF and glucocorticoid (GC). Clinical outcomes and adverse side effects are reported. Eleven dogs diagnosed with PF. Retrospective review of medical records from dogs presented with PF to the dermatology service of a veterinary teaching hospital between 2015 and 2020. Eleven dogs were identified which had received concurrent GCs and MMF. The MMF dose range was 19.8-45 mg/kg/day. Only two dogs (two of 11) treated with a mean MMF dosage of 39 mg/kg/day along with oral prednisone or dexamethasone achieved complete remission (CR). Partial remission (PR) was achieved in four of 11 dogs who received either prednisone, prednisolone or dexamethasone along with MMF (mean dosage 26 mg/kg/day). Four dogs (four of 11) showed poor response to MMF given at 28.5 mg/kg/day along with prednisone or dexamethasone. In one dog (one of 11) MMF was discontinued due to severe GI upset; transient vomiting and diarrhea was observed in four of 11 dogs. The median duration of MMF therapy in conjunction with GC for all groups was 70.5 days. Tapering of oral GCs while continuing MMF administration at the same dosage and frequency led to recurrence of lesions in all PF patients. Oral MMF combined with GC achieved CR in two of 11 PF dogs included in this study. Further research of MMF efficacy in PF may need to be performed.