Cattle Dog is a label more than a single breed. Most dogs listed this way are Australian Cattle Dogs, the Blue and Red Heelers, or mixes with one. The breed was developed in 19th-century Australia to drive cattle by nipping at their heels. Others carrying the label are Texas Heelers or crosses with Border Collies, Labs and many more.
A typical adult is medium-sized, around 30 to 50 pounds, muscular, with a short double coat that sheds moderately. They're smart, tireless and devoted to their people, and they tend to be wary of strangers. In Concord that adds up to a dog that thrives on greenway miles and training games, and struggles when left alone with nothing to do. Size, coat and energy vary in mixes, so the dog in front of you matters more than the label.