Horse Armor Cannot Be Placed on a Tamed Horse

While playing on a survival realm, created in v1.1.3, I decided to get a horse. After taming it, i put on it's saddle, but when I tried to put on it's horse armor, 1. It didn't have the armor slot picture (In screenshot) 2. It wouldn't go in the slot, nor appear on it.
I was playing on Minecraft: Windows 10 Edition.