Treatment of Canine Pemphigus Foliaceus, Pemphigus Vulgaris and Mucous Membrane Pemphigoid With Oclacitinib: A Retrospective Analysis of 21 Cases

BACKGROUND: This study was performed to retrospectively evaluate the efficacy of oclacitinib (OC) (Apoquel; Zoetis) as a treatment option for pemphigus foliaceus (PF), pemphigus vulgaris (PV) and mucous membrane pemphigoid (MMP). OBJECTIVE: To determine if OC can reduce or replace the corticosteroid use in dogs with PF, PV and MMP. ANIMALS: There were no animal subjects. PROCEDURE: Multicentre retrospective study reviewing medical records from two institutions for dogs diagnosed with PF, PV or MMP and prescribed OC between 2014 and 2025. RESULTS: Twenty-one dogs diagnosed with PF, PV or MMP via histopathological results were included. OC alone was effective in eight of 18 PF dogs at a median dose of 0.65 mg/kg/day per os (range 0.5-1.9 mg/kg/day p.o.). Five dogs reached clinical remission, and three reached partial remission. One PV dog and the MMP dog each reached clinical remission with OC alone at 0.7 mg/kg/day and 0.24 mg/kg every other day, respectively. OC was a corticosteroid-sparing agent or adjunctive therapy in seven of 18 PF dogs at a median dose of 0.6 mg/kg/day (range 0.4-2.4 mg/kg/day). One PV dog reached partial remission at OC 1.9 mg/kg/day and prednisone 1.8 mg/kg/day yet died from pancreatitis. OC was ineffective in three of 18 PF dogs at a median dose of 1.0 mg/kg/day p.o. (range 0.9-1.2 mg/kg/day p.o.). Statistical significance was not analysed. CONCLUSIONS AND CLINICAL RELEVANCE: OC is an effective sole therapeutic agent or adjunctive therapy in a subset of dogs with PF, PV or MMP. The long-term safety of higher doses of OC is unknown.