What is the true definition of a ‘purebred’ dog?

What is the true definition of a ‘purebred’? Merriam Webster stated that it’s ‘bred from members of a recognized breed, strain, or kind without admixture of other blood over many generations’. But it is actually dodgier that you think:The Cesky Terrier was created in 1949 by crossing the Scottish Terrier with the Sealyham Terrier. So why aren’t they considered as designer dogs?You may say that they are recognised by reputable kennel clubs. What about the Akbash Dog which had more than 3000 years of history?If Teacup Poodles aren’t really a breed, why are Miniature American Shepherds in AKC’s FSS?What about a strain of dog? Why is the Berger Blanc Suisse considered different from the American White Shepherd while working and showing Bedlingtons are classified as one breed? What about Japanese and American Akitas? Are they one breed or two?

Baptised Dog

when it will bred true, it is consider a breed

Bred from parents of the similar breeds OR variety.

There's no such thing as a purebred. There are only mutts and inbred mutts ("purebreds").Breeds are a nice classification of inbred mutts, useful information if you want to a dog best suited for a specific purpose or to know a general temperament prediction, but beyond that it doesn't mean squat, IMO.

Of course dogs were originally 'made' by selective breeding. However, it's not until a certain strain of dogs 'breed true' that a dog can be considered purebred - in other words after many generations you will always get a dog that conforms to the Breed Standard for it's breed, which was originally drawn up by a group of people who got together to standardise what they were producing, and had it ratified by the relevent KC.I haven't checked specifically, but you'll probably find there are differences in the Breed Standards of the breeds you mention, which makes them separate breeds. There are differences country to country too - for instance the Miniature American Shepherd isn't a recognised breed in the UK. However teacup-anythings are NOT recognised anywhere because they do not breed true. As is the case with all this 'doodle' - nonsense (much as I have a suspicion the people breeding Labradoodles are getting pretty close to them breeding true - coats apart!!!)It's not so much the mixture of other blood ....... but all about whether you can reliably put a male of one breed with a b itch of the same breed, and get a litter of puppies who are all the same, without seeing a throwback (much as this can still happen).