Abstract
A twelve-year-old female Shetland sheepdog was referred to our hospital for a large tumor mass around the anus. More than a half part of the external sphincter ani muscle should be removed to excise this mass. For the reconstruction of the anus, the levator ani muscle was used to avoid fecal incontinence. The function of the anal sphincter was quite good without fecal incontinence after the surgery, indicating this repairing procedure to be the choice of treatment in the patient with large anal masses.
