By Mandy Cha, DVM
Laminitis is a very scary word in the equine world. It is the cause of lameness, pain, loss of performance, and very unfortunately, can be the cause of euthanasia in horses. It can be particularly frustrating as it cannot be “cured” – only managed, and the damage sustained from an episode can be irreversible.
Laminitis is defined as inflammation of the laminae – the convoluted infoldings of tissue that adhere the horse’s hoof to the coffin bone. The blood supply to the laminae is simultaneously extensive and delicate. In the event of damage to the blood supply, the tissue starts breaking down, and the hoof wall effectively begins to tear away from the foot under the weight of the horse. This is colloquially termed “founder”.
What leads to this damage? Unfortunately, any cause of total body inflammation can lead to laminitis. These include infections (such as pneumonia), complications from foaling (such as a retained placenta), and colic. Repeated concussive trauma to the foot can also lead to laminitis, in this scenario called “road founder”. Severe injury to one leg and subsequent excessive weight bearing on the opposite limb can also cause laminitis, called “support limb laminitis”. This was the cause of death for Barbaro, a famous racehorse who sustained a fracture during the 2006 Preakness Derby. We are also learning that two common metabolic conditions can predispose to laminitis. These are called Pituitary Pars Intermedia Dysfunction (PPID, “Cushing’s Disease”) and Equine Metabolic Syndrome (EMS).
Common early signs of laminitis can be more subtle than the traditional “saw-horse stance” described in many articles. These include generic signs of foot pain, including:
· A stiff, stilted gait
· Bounding digital pulses
· Excessively warm hoof capsules
· Difficulty making a tight turn
· Reluctance to move
· Reluctance to walk on hard surfaces
Although these signs may sound similar to simple, less scary conditions, such as thin soles, osteoarthritis, or even a foot abscess, it’s important to check and make sure that the horse is not undergoing laminitic changes, especially if he has any of the predisposing factors listed above. Checking digital pulses is a simple, specific way to tell if your horse has laminitis. Simply place your index finger and thumb on the squishy vessels on the back of your horse’s fetlocks. If you can feel the blood pumping against your fingers, it may be a sign that you need to start helping him manage laminitis.