The issue with dalmatians is that that 100% of them have some genetic issue (kidney failure?) and back in the late 70's or 80's the crossed in one generation of another breed and it cured them of this issue.
Even now, the dogs from that project, even though 99.99% dalmatian are not allowed to be registered as a dalmatian. The reason being is because the majority of the club don't want their advantage taken away. Allowing these dogs in would be a huge benefit and make the breed healthier.
It can go either way. It all depends on how the majority of the club members (or officers?) feel.
Yet other "breeds" thrive on being mixes and want to get acceptance (Inuits) or want their own selective breeding program to be it's own breed (Shiloh Shepherds).
Other times mixed litters are born and paper work is falsified. I know of a malinois / Dutch Shepherd litter but the "breeder" sold them all off as pure malinois (he even got someone who is very well known to sign off on the paperwork so they could get them registered as pure).
Its getting harder to even tell if "purebreds" if they real purebreds or not.
