Seriously, "horse books" might as well been their own subgenre. Judging from my children's librarian days, they don't seem to be as popular anymore - at least, the little being published seems to be mostly in series aimed at younger readers than I was when I lost interest. And I'm not quite sure what all that horsey literature did for me, except that I do know what a stakes race is...

(Also, to this day, I can describe all the genetically possible color combinations for offspring from a given pair of horses. Highly transferable skill, that. :p )