Miniature horses are built exactly like their full-sized fellow equines, but along with their small stature come some health problems seen less often in larger equines.
Similar to dog breeds that have been selectively bred for their appearance, years of breeding horses for small size has inadvertently made minis much more susceptible to conditions that can affect them throughout their lives. The two main condition categories are congenital and acquired. A congenital disorder means the animal is born with the problem, whereas acquired means the problem arises after the animal has been born.
Born That Way
For example, in the first category, Miniature horses are more often affected by congenital angular limb deformities than normal-sized horses. Angular limb deformities occur when the leg deviates from its normal axis (is crooked). Depending on the severity of the deformity, corrective shoeing can sometimes fix the problem. If unsuccessful, surgery is required to encourage the bone to grow straighter. It is important to speak to your vet sooner rather than later if you see your Miniature foal with a leg that does not look normal.