Dog bites may lead to bruising, because the dog’s teeth are not as sharp as needles or knives, so most bites are mainly contusions of local subcutaneous soft tissues, usually combined with a little superficial skin damage, bleeding. Therefore, in addition to bleeding, there may be a rupture of the capillaries under the skin, bleeding, resulting in bruising of the subcutaneous tissue, which does not appear immediately when first injured, and will only slowly appear after 24 hours of injury.