Tattoos are sometimes used by forensic pathologists to help them identify burned, putrefied, or mutilated bodies. As tattoo pigment lies encapsulated deep in the skin, tattoos are not easily destroyed even when the skin is burned.Tattoos are also placed on animals, though rarely for decorative reasons. Pets, show animals, thoroughbred horses, and livestock are sometimes tattooed with identification and other marks.
Tattooing with a ‘slap mark’ on the shoulder or on the ear is the standard identification method in commercial pig farming. Branding is used for similar reasons and is often performed without anesthesia, but is different from tattooing as no ink or dye is inserted during the process, the mark instead being caused by permanent scarring of the skin. Pet dogs and cats are sometimes tattooed with a serial number (usually in the ear, or on the inner thigh) via which their owners can be identified. However, the use of a microchip has become increasingly an increasingly popular choice and since 2016 is a legal requirement for all 8.5 million pet dogs in the UK.