The skin is smooth and warm to the touch. The Hairless variety may sweat when overheated or stressed, but this is not to be faulted in the ring. Vellus hair longer than 1mm on a dog over six months of age. The white area may be ticked as long as white predominates. Colored areas may have sable overlay.
Any skin color is acceptable.
The skin is usually parti-colored with an underlying skin color and freckles or spots of contrasting color. Freckles enlarge with age, and skin color will darken when exposed to the sun. Weight will vary depending on the size of the individual dog. Rat Terriers are working terriers and should be presented in hard, muscular condition. The Rat Terrier moves with a jaunty air that suggests agility, speed, and power.