A Case of Actinic Keratosis in a Rabbit

Actinic keratosis is well described in humans, dogs, and cats as a precancerous skin growth caused by ultraviolet light–induced DNA damage. This report describes a case of early actinic keratosis in a 6-year-old rabbit (Oryctolagus cuniculus). On dermatological examination, erythema and yellow adherent scales were observed on the external aspect of the pinnae. Mild pruritus was also present on the initial presentation. Histopathology revealed segmental epidermal hyperplasia with loss of polarity in the basal layer. Mild nuclear atypia and marked orthokeratotic hyperkeratosis were present. The superficial dermis had marked reticular fibrosis with thickening of collagen fibrils. Topical treatment with diclofenac resulted in clinical resolution of the disease.