Complex sentence: However, the term "pony" can be used in general (or affectionately) for any small horse, regardless of its actual size or breed, and some horse breeds may have individuals who mature under 14.2 but may still be allowed to compete as horses.
Split into simpler sentences: However, the term "pony" can be used in general (or affectionately) for any small horse, regardless of its actual size or breed. Furthermore, some horse breeds may have individuals who mature under 14.2 but are still called "horses" and are allowed to compete as horses.