From publisher blurb:
Call to Arms: Horses & Mules contains information on how to more accurately use horses, mules and other equids for transport, roleplay information including a horse personality generator and glossary of horse colors, information on when and why you might want a mule rather than a horse as well as stats for new horse "types." You will also find horse-like monsters and mounts, and examples of "mythic" and "artifact" horses, some of them new to this book. It draws on real life horse knowledge as well as mythical horse-like creatures from around the world. Horses & Mules is for the GM who wants to make overland travel more realistic and a key part of the game as well as players of mount-focused classes, such as the Cavalier or Paladin. Horses are a vital part of Medieval-style and other low-tech settings and this book will help you do more with them than tie them up at the dungeon entrance and hope they are still there when you get back.
Information about horse physiology, psychology and health
New horse and mule types
New feats for both riders and mounts
Hussar (Cavalier variant class) and archetypes
New horse-like monsters and mounts
and more