A dog's ear is tattooed once he receives his registration number from the KCP. Pedigree would tell you about the breed, temperament, bloodline etc of the dog. Along with the guarantee that it is a pure breed.
A non pedigree dog can also be pure, very good bone structure and have awesome blood lines. Mainly your dog will grow up to be what you train it to be.
It depends on you what you want to buy, some people buy pedigreed dogs just to show off and give the dog a fancy long name. Other people are breed conscious. For people like me, I prefer a good deal. A healthy nice dog in good price, pedigree or non pedigree is secondary. for you, you have to pick what you neeed. and remember your dog will grow up to be, what you train it to be.
