The short answer is yes - it is possible for a dog to have tan points and NOT be at/at, however it is very rare. Although at is recessive to sable (Ay) and agouti (Aw), there is a fourth allele on that locus - recessive black (a) - which is extremely rare, but recessive to at. Which means a dog that with tan points, in theory, could be either at/at or at/a.I've searched far and wide for answer to my main question and yes read through the site you mentioned.
I know black n tan dogs are at at, theoretically tri color in the regards of 'tan point marking'. I been led to understand that to whelp a tan point you need 2 copies of at. Ay Sable overides at.
Is there any chance of producing even one tan point from anything other than two at factored?
Secondly, I need a bit more clarification - do you know for sure that the e/e dog is NOT at/at? Because a dog can be both e/e AND at/at - it just won't show the tan points because those tan points will be the same colour as the rest of the dog.How about the possibility of an ee dog with no chance of at to mate with an atat? The reason I ask is that I'm in NZ and there are simply no bnt dogs. NZ only has 4'000 poms anyhow and most are pet dogs with no special breeding, and infact 6kg dogs (3kg over a true pom).
Any help is appreciated, and also as I mentioned I'm happy to give advice on anything other than this bnt issue ?