Carly the female Cattle Dog / Sheltie mix at 1 year old—"Carly has high energy and loves to play fetch. She is overall a good dog who likes to bark."
The Sheltie Heeler is not a purebred dog. It is a cross between the Shetland Sheepdog 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.