So we finally determined our rescue is NOT a Stumpy Tail after finally finding a breed standard website stating that they should not have tan markings mixed with blue (which she does). So it's been determined that she, in fact, an ACD but she was born with a bobtail. So my question is (to determine if she's a mix or not because she looks like breed standard otherwise) are there occasionally heelers born with bobtails? It's already been determined that it was not docked. Or is she the result of someone thinking a stumpy tail was a heeler with a docked tail? I found a couple fly-by postings by anonymous users that they had picked out a bobtailed puppy from a litter of heelers with tails but I was curious to what you guys say. (This is just to serve my insatiable curiosity)