Diamond and Shirley, adult Rottweiler / Australian Cattle Dog mix breed dogs (Rottie Heelers)—"We have a male Australian Cattle Dog and a female Rottweiler. We had successfully, for a few years, managed to keep them apart to avoid mating, but nature found a way."
The Rottie Heeler is not a purebred dog. It is a cross between the Rottweiler and the Australian Cattle Dog. The best way to determine the temperament of a mixed breed is to look up all breeds in the cross and know you can get any combination of any of the characteristics found in either breed. Not all of these designer hybrid dogs being bred are 50% purebred to 50% purebred. It is very common for breeders to breed multi-generation crosses.
Note: the Australian Cattle Dog is also called Australian Heeler, Hall's Heeler, Queensland Heeler, Blue Heeler, Red Heeler, Australian Cattledog and Australischer Treibhund.