The following information is copied verbatim from "Your Purebred Puppy, A Buyer's Guide" by Michele Lowell -- an excellent, invaluable book with information on over 160 dog breeds.
Australian Cattle Dog
For Experienced Owners Only
Good with Older, Considerate Children
Medium in Size
Short Coat

EXERCISE REQUIRED
TRIMMING/CLIPPING REQUIRED
AMOUNT OF SHEDDING
ACITIVITY INDOORS
EASE OF TRAINING
SOCIABILITY WITH STRANGERS                              
High          Med          Low
8=8
                                   8=8
                 8=8
                 8=8
                 8=8
                                   8=8
Temperament

          He is a bold, hardy worker and a capable, watchful companion.  He belongs in the suburbs or country where he can get the hard exercise he needs; he doesn't like to be cooped up with nothing to do.  To keep his mind and body busy, he should work stock or be trained in obedience.  Reserved and protective with strangers, he should be accustomed to people at an early age.  He's smart but also clever at getting his own way; he's obedient but with an independent streak.  He can be aggressive with other animals.  He could bite if harshly treated, and he can nip at people's heels as though trying to herd them.  Some can be barkers.  Some are a bit timid or high-strung.  Ongoing exercise, socialization, and activity are necessities with this breed.
History

          He was developed in Australia to work with wild cattle.  Crosses between the Scottish Highland Collie, the wild Australian Dingo, the Dalmation, and the Austalian Kelpie produced a hardworking, protective dog often called the Queensland Blue Heeler, because he tends to bite at the heels of the cattle in order to drive them.  He is first a working stock dog, second a companion.  AKC popularity: 64th of 130 breeds.
Physical Features
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He stands 17-20 inches and weighs 35-50 pounds.
His coat is straight with a dense undercoat, and should be brushed once a week.  He's usually blue-mottled (a mixture of blue, white, and gray), with tan markings on his head, chest, and legs, possibly with black markings on his head.  He can also be red-speckled (white with many red flecks), possibly with darker red markings on his head.  Puppies are born white.
His ears prick up.  His eyes are dark brown with a suspicious expression.  His nose is black.  His teeth meet in a scissors bite.
Fualts: A blue-mottled dog should not have any black markings on his body.
Health Problems

          He is susceptible to hip dysplasia, PRA, and congenital deafness.  Buy only from OFA-registered parents.  Test puppies' hearing by clapping and whistling.
Cautions when Buying

          If you're looking for an AuCaDo (AW-ca-doe) for a companion, don't buy from strict working lines, because this kind of dog may be too intense and businesslike to be at his best as a pet.  Don't choose the boldest or most independent AuCaDo puppy, and don't choose a timid puppy.