Ear Tip Ulcerative Dermatitis Treated With Oclacitinib In 25 Dogs: A Retrospective Case Series

Background Ear tip ulcerative dermatitis (ETUD) is an uncommon clinical reaction pattern in canine dermatology. The lesions are suggestive of vascular damage which may be caused by inflammatory or noninflammatory diseases, and often are idiopathic. Therapeutic options for ETUD include topical glucocorticoids or tacrolimus, pentoxifylline, vitamin E, doxycycline, tetracycline and niacinamide, sulfonamides, glucocorticoids, ciclosporin and surgical correction. Hypothesis/Objectives The aims of this retrospective case series were to describe the clinical features and report response to treatment with oclacitinib in dogs with idiopathic, chronic ETUD. Animals Twenty-five privately owned dogs with unilateral or bilateral ETUD. Methods and materials Cases of ETUD which were poorly responsive to conventional therapy and subsequently treated with oclacitinib, are summarised. All cases were tested for leishmaniosis by serological examination [indirect fluorescent antibody test (IFAT) or enzyme-linked immunosorbent assay (ELISA)]. Histopathological examination was performed in two cases. Results Serological results were negative for leishmaniosis in all dogs. Histopathological changes consistent with proliferative thrombovascular necrosis of the pinnae were documented in two cases. Oclacitinib, used at the standard dose range recommended for the treatment of canine atopic dermatitis, effectively resolved ETUD in 22 of 25 dogs within one to three months. Several of the dogs required prolonged use of twice daily dosing. Conclusions and clinical relevance Oclacitinib should be included among the therapeutic options for ETUD, once infectious diseases have been ruled out.