Joe and the Race to Rescue by Victoria Eveleigh

Joe is fascinated by every horse he meets. Lightning is a pony club champion, but new challenges await Joe with his second pony, Fortune. Then he meets two majestic Shires, who open his eyes to the world of heavy horses. Joe is about to discover just how awesome Shires can be when they help him in a dangerous and dramatic rescue at the Hidden Horseshoe sanctuary. 
 
Suitable for ages 12+