AbstractA 9‐month‐old mixed‐breed dog developed generalised pustular dermatitis, accompanied by lethargy and hyperthermia, 7 days after oral fluralaner administration. Dermatopathological and microbiological evaluations were consistent with a pustular acantholytic dermatitis. A 4‐month course of immunosuppressive therapy resulted in complete remission of lesions, which did not recur after therapy was withdrawn.