A Look Inside Laminitis

Keys to understanding this debilitating and life-threatening disease

Laminitis is inflammation of the coriums. In a healthy hoof the hoof wall is tightly attached to the bone inside. The bone and hoof wall both have structures call laminae attached to them and these laminae interlock with each other to form a very tight bond.

      When your horse has laminitis there is inflammation between the two sets of laminae. This is extremely painful as, unlike inflammation in soft tissue where the tissue can swell, the hoof capsule and bone are both very rigid which means that the swelling results in a huge amount of pressure that has nowhere to go.

      Laminitis is a major disease of horses because of the associated pain and debilitating nature which makes it a life-threatening condition. It presents itself as a physical problem due to the way the hoof laminae support the horse’s weight and the vascular system in the foot, which is particularly sensitive to systemic inflammation originating in the intestine or uterus.

A LOOK INSIDE

Research on equine laminitis has unraveled many of the physiologic responses that occur within the horse’s foot. However, the exact cascade of events which lead to damaged laminae with eventual separation of the coffin bone from the cornified hoof is not completely understood.

             On the outer hoof wall grows. The damaged, disorganized laminae, responsible for the inner hoof wall production and the white line, will not grow good inner hoof wall. The most surprising observation is the sole corium. It has pulled forward and over the front edge the coffin bone. Essentially, there is sole now growing between the hoof wall and the coffin bone.

            The hoof on the left just needs a trim, whereas the foot on the right needs a specific, targeted and intensive approach. A hoof with this much damage may or may not improve.

THE LAMELLAR WEDGE

In this sagittal view of the same pair of hooves, we can clearly see the rotation of the hoof capsule. In the healthy hoof, the leading edge of the coffin bone and the hoof wall are parallel to each other (blue lines). However, in the laminitic hoof they are no longer parallel and there is a significant lamellar wedge filling the gap.

            Also, in the affected foot, the sole corium has migrated up and over the edge of the coffin bone. The white arrow indicates where the sole has grown up and around the tip of the coffin bone. When this occurs, the sole is no longer growing in the correct place, which makes the edge of the sole an unreliable landmark to follow when trimming and can lead to major distortion in the toe area.

            Laminitic hooves do not grow "normally" and our photographic evidence helps show why. Deciphering the changes that occur to unhealthy hooves can be very tricky, which is why it is vitally important to understand the underlying anatomy. This aids us in figuring out what is actually happening and provides inspiration for ways to help these compromised horses.

Exploring Laminitis 1

eBook and iPad App

61 page eBook that is compatible with any computer, laptop, smart phone or tablet and is also available as an iPad App. Using comparative anatomy dissections showcase in stunning full color detail, the effects of chronic laminitis on the equine hoof.

  • Stunning, high resolution, full color dissection photos and illustrations
  • Easy to navigate
  • Explore beneath the skin to fully understand the structures
  • Comparative anatomy of a normal and laminitic hoof
  • Clearly labeled structures
  • Close-up views

Available at www.anatomy-of-the-equine.com/exploring-laminitis.html

Jenny Edwards is a professional hoof care provider and author of Equine Laminitis, a practical guide written to help equine caregivers navigate the complexities of Laminitis (www.all-natural-horse-care.com/equine-laminitis.html)

Jenny has joined forces with fellow professional, Paige Poss (www.ironfreehoof.com) to create dissection-based educational material. Their most recent project called Exploring Laminitis uses comparative anatomy dissections to give insight to the effects of laminitis on the hoof: www.anatomy-of-the-equine.com/exploring-laminitis.html

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