How Big Is The Smallest Horse?

The world's smallest horse is officially Thumbelina, who is (full grown) only 17 inches tall and weighs just 57 pounds.

Unfortunately, Thumbelina is a bracycephalic dwarf.

(Image Phil Konstantin via Wikimedia Commons).

As you can see, she has exceptionally short limbs, a bulging forehead, swollen knees, a pot belly and a very flat back as well as a short neck - all characteristics of dwarfism in equines. Many dwarfs have joint problems, premature arthritis, back issues and organ defects...some are sterile. Because of this, dwarfism is considered a curse in miniature horse breeding...