Double Dew Claws

In conversation about a homeless dog that is presumed to be a Lab/GSD mix,
(5 or 6 years old, 45 - 50 pounds) it has turned out that she has double dew
claws (don't know if it is front or hind legs). I know of a handful of dogs
that have double dews, most of which are rare breeds, and am wondering what
the possibility is that this dog is a purebred something rare with double
dews, or a mix thereof, and if it is possible for her to indeed be a Lab/GSD
mix (or some other sort of Heinz) and still have the double dew claws.
Anyone know what the mode of inheritance is for this trait?

Suja

"Suja" <spanaval.TakeThisOut@yahoo.com> wrote in
news:5pbjo7FpndntU1@mid.individual.net:

> double dew claws (don't know if it is front or hind legs). I know of
> a handful of dogs that have double dews, most of which are rare
> breeds, and am wondering what the possibility is that this dog is a
> purebred something rare with double dews, or a mix thereof,

Several herding or LGD breeds have double dew claws on back legs quite
regularly, they are just most often cut away when they are pups unless the
breed standard requires them.

Dunno about Labs or GSDs, but wouldn't count them as "totally impossible"
for GSDs, as they are indeed originally a herding breed.

Liisa