Ideally, dogs 18" to 20" - bitches 17" to 19".
There are only two recognized colors of Australian Cattle Dogs--blue (a combination of gray, black, and silver/white) and red (a combination of red, brown, and silver/white)--and both these colors must have an overlay of silver or white guard hairs. Markings include half and full masks (solid black on blue or solid red on red), the white forehead or Bentley mark, speckling or mottling, and ringed or solid tails. Eyes must be as dark brown as possible and full dentition with a scissors bite is required.