* Breed recognition is subjective: Different organizations and registries may recognize different breeds.
* New breeds are developed: Breeders continue to create new breeds through selective breeding.
* Some breeds are "landraces": These are horses that have evolved naturally in a specific region and haven't been formally recognized as a breed.
However, it's estimated that there are over 300 recognized horse breeds worldwide.
It's important to note that this number can change frequently as new breeds are developed and recognized, or as some breeds become extinct.