Equine laminitis is a painful condition resulting from cellular damage and inflammation of the laminae due to reduced blood flow to the hoof

Equine laminitis is a painful condition resulting from cellular damage and inflammation of the laminae due to reduced blood flow to the hoof. Laminitis can be caused by an over consumption of nonstructural carbohydrates,NSC, the sum of simple sugars, starch, and fructan. Pasture grass is the main diet for many horses and reducing intakes of pasture NSC can prevent the onset of laminitis for horses at risk. For the majority of horses, total pasture restriction is not an option but there are many ways to lower the risk of laminitis for horse’s on pasture. Understanding what animals are at risk influences how to manage them. Many horses can remain on turnout with the use of grazing muzzles or reduced durations while some may need to be on a dry lot and fed hay low in sugars. Pasture management however can be difficult as species, light intensity, seasons, and temperature all affect the levels of nonstructural carbohydrates that can accumulate within a plant.
Introduction
Laminitis occurs throughout the world in horses and ponies and has major lasting effects on equine care and maintenance. Laminitis does not have a known precise cause, but many causes are linked to equine nutrition with the over consumption of nonstructural carbohydrates,NSC. Nonstructural carbohydrates are the sugars, starches, and fructans that are digested to provide energy, however, over consumption can have many damaging effects. Laminitis is a crippling disease where the blood flow from the laminae is affected, resulting in inflammation and swelling in the tissues within the hoof. This starves the laminae of oxygen and nutrient rich blood and if treatment is not begun immediately the laminae will begin to detach and die. The laminae are responsible for supporting the coffin bone and the hoof which support the entire weight of the horse. In severe cases, the laminae are no longer able to support the hoof from the pull of the deep digital flexor tendon and the horse’s weight. If the coffin bone sinks or rotates far enough, it can protrude though the sole of the hoof where the damage is inversible. Longland and Byrd (2006) reported that the overall the annual incidence of laminitis in the U.S. is 2% but rises to 5% in the spring and summer, and nearly half of all reported cases of laminitis in the U.S. occur in animals at pasture. Though it is not precisely known what causes laminitis, pasture-associated laminitis focuses on the over consumption of NSC rich grass. Current research is focused on understanding the mechanisms behind laminitis, what animals are at risk of laminitis and strategies to prevent large intakes of NSC.