Never look a Defective Horse in the mouth

At least 30 times a day someone asks me: "How do I know if my horse is defective?" Sadly, it's always the same guy asking me that, and I'm pretty sure he doesn't own a horse, because he lives on the seventh floor of a no-pets apartment and rides a scooter to his job at Jiffy Lube.

In any case, I hope my handy chart here sheds some light on defective horses, most of which probably aren't horses at all.