Sheep have a sebaceous (oil) gland in the skin of the interdigital space. A thick, oily, translucent secretion is stored in a small pouch lying between the phalanges and is discharged to the skin surface through a duct in the skin. Occasionally, the gland and its contents are mistaken for an abscess. However, the duct can become occluded, causing distention of the oil pouch. It rarely causes lameness. The oil sac also may become infected, resulting in a local cellulitis or abscess that may be confused with bumblefoot. Expression of the contents by manual pressure relieves impaction. Infected glands can then be treated with local or systemic antibiotics or both, depending on the extent and severity of the infectious process. Unlike bumblefoot, this condition generally responds readily to treatment.
Last full review/revision December 2013 by Marie S. Bulgin, DVM, MBA, DACVM