A 2-yr-old female lesser kudu (Tragelaphus imberbis australis) was presented for lethargy. Empirical antibiotic treatment appeared to improve its clinical signs, although no etiology for the symptoms was determined. The kudu again presented with lethargy, diffusely swollen limbs, and subcutaneous ecchymoses of 1 day's duration after completion of the initial therapy. Vasculitis secondary to presumptive leptospirosis infection was diagnosed based on a skin biopsy and decreasing paired serologic titers for Leptospira grippotyphosa. The vasculitis was responsive to intramuscular antibiotic therapy and dexamethasone treatment. This case provides evidence that corticosteroids can be used in ruminants at moderate doses for chronic treatment without clinically relevant detrimental effects.