An 8-year-old Boston terrier was brought to Kitasato University Veterinary Teaching Hospital with chief complaints of swelling in the vicinity of the right rear mammary gland, lethargy, and anorexia. The results of various examinations suggested a juxta-mammary abscess, resection of which led to the diagnosis of an irreducible inguinal hernia. The hernial sac contained pyometra of both uterine horns and ovaries. The uterus and ovaries were removed without having to make another incision in the abdominal wall. The postoperative course has been uneventful
