Over the past several million years, horses have evolved from the Eocene era's Labrador-sized mammal to today's modern, domesticated equine. In studying the Equus species' fossil record, researchers have discovered evidence of sidebone, ringbone, arthritis, navicular disease, and other hoof conditions, but until recently they've documented no reports of laminitis. Many have chalked this up to a lack of human influence and predation of vulnerable animals, but Lane Wallett, DVM, a PhD candidate in the University of Florida College of Veterinary Medicine's Department of Physiological Sciences, wasn't convinced. So she conducted a study of ancient equine coffin bones and presented her findings at the 2013 International Equine Conference on Laminitis and Diseases of the Foot, held Nov. 1-3 in West Palm Beach, Fla.

"Chronic laminitis in horses has long been conceptualized as a disease of domestication, a result of husbandry practices replacing wild behavior and nutritional patterns," Wallett said. "However, the growing body of research suggests that the disease may be common in modern feral horses."

Factors Wallett believes contribute to laminitis' natural development through the ages include horses' digit reduction from five to one and their transition from short to high-crowned hypsodont (constantly erupting) teeth.

"Dentition transition means nutrition transition," she said. "It correlates with the rise of grassland and horses going from browsers to grazers and consuming more carbohydrates (as high-carbohydrate diets have been linked to laminitis development)