I'll also add that the regulations put on classifying a thoroughbred as a registered thoroughbred enforces inbreeding.

We are seeing less and less throughbreds in the show rings because they tend to be the dumbest of the breeds, for good reason - they are so inbred. So, it seems that if this practice of racing them so young combined with such control for registry discouraging genetic diversity and the fact that less and less of them are being seen in the show rings (still they are quite prevalent), the breed itself might actually be completely destoyed for lack of use after racing rejection and lack of genetic diversity.

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