The Rottweiler (/ˈrɒtwaɪlər/, UK also /-vaɪlər/) is a breed of domestic dog, regarded as medium-to-large or large. The dogs were known in German as Rottweiler Metzgerhund, meaning Rottweil butchers' dogs, because their main use was to herd livestock and pull carts laden with butchered meat to market. This continued until the mid-19th century when railways replaced droving. Although still used to herd stock in many parts of the world, Rottweilers are now also used as search and rescue dogs, as guard dogs, and as police dogs. The undercoat should be present on the neck and thighs. The undercoat must not show through the outer coat. Rottweilers living in hot climates may have acclimatised and may be missing the undercoat. Rottweiler coats tend to be low maintenance, although they experience heavy shedding before their seasons (females) or seasonally (males). According to American Kennel Club breed standards, a Rottweiler's coat is short and straight. A coat that is long or wavy is considered a flaw to the AKC.