@BART:
While he isn't purebred (lack of white tells us so), there aren't many breeds that curl their tails. And Basenji's tailbones actually curl towards the end, they couldn't totally straighten it out if they wanted to. That said, I still think he probably has some Basenji in his genes….and he's still cute as the dickens. More stories and photos - a must:)
Actually all of the Spitz type dogs have a tail that curls over the back (Akita, Shiba, Malamute, Husky, etc). The double curl of the westernized Basenji has been added by breeders. Often Rat Terriers have a curled tail if it isn't docked, possibly because there is Basenji back in the lineage to create the breed. And lots of Basenjis have a tail that ONLY curls up over the back. Not all B tail bones curl at the end…Some of my dogs have super tight curls that you can't "undo" and some of mine relax their tails quite frequently.
I don't want it to seem like I am arguing with you, 'cause I think I agree with what you are saying. But I just wanted to clarify a little about Basenji tails.