Lokivetmab improved pruritus in a dog with cutaneous epitheliotropic lymphoma.

A 13-year-old spayed female Cavalier King Charles Spaniel presented with chronic swelling and pruritus on the palmar aspect of the left forepaw and on the tail. Cutaneous epitheliotropic lymphoma (CEL) was diagnosed by histopathology and immunocytochemistry. Prednisolone was initially used alone as an alternative treatment for CEL. Despite long-term corticosteroid therapy, the patient's physiological (pruritus) and dermatological signs (alopecia, erythema, erosion, and ulceration with crust) progressed and showed no evidence of improvement. To address the worsening condition of pruritus, lokivetmab was started in combination with prednisolone. Once on lokivetmab, the pruritus steadily improved and was effective in resolving and maintaining remission. Further investigation on the critical role of IL-31 in the pruritus pathway of dogs with CEL is required.