The Dalmatian is a breed of large-sized dog, noted for its unique white coat marked with black or liver-coloured spots and used mainly as a carriage dog in its early days. Spots usually range in size from 20 to 60 mm (1.25 to 2.5 in), and are most commonly black or liver on a white background. Liver is the recessive color in dalmatians, meaning that both parents have to “carry” liver in order to produce liver pups. If both parents are liver, then all puppies will be liver spotted. Dalmatians are associated with firefighting, particularly in the United States. Dalmatians were a popular breed for this job, due to their natural affinity to horses and history of being used as carriage dogs. This role became unnecessary once horse-drawn fire engines were replaced with steam and diesel powered ones. Due to its history, the Dalmatian often serves as a mascot for the fire service, and is still chosen by many firefighters as a pet.