(lockney texas usa)
how do i know if my rottweiler is full blooded?
The only way to be sure a dog (of any breed) is purebred, or full-blooded, is if the parents both have registration papers from the AKC (or a similar organization) and if the litter the pup is from is also registered.
Other than that you have to take the breeders word for it, and it’s sometimes impossible to tell just by looking. A responsible, reputable breeder will have dogs who are registered.