Comedones and epidermal cysts on the abdominal skin of a dog occurring after a laparotomy.

An 8-year-old neutered male shih tzu dog underwent laparotomy for cystolithectomy. Ten days later, multiple various-sized cystic nodules were observed on the suture line and surrounding abdominal skin, although the surgical incision had healed well. Microscopically, various-sized cysts lined with thin walls of stratified squamous epithelium in the dermis were dilated and filled with keratin.