Bob Childs - ESA/AHA/PHCP Certified Hoof Specialist
Interesting comments on laminitis and obesity by Donald M. Walsh, DVM
"Based on my experience observing laminitic horses over the past 36
years in veterinary practice, I believe that obesity leads to the
development of weakened laminae and other supporting structures of the
foot and to changes in the growth pattern of the feet. 2 Radiographs
reveal that the appearance of the laminae begins to change in horses
that are becoming obese, even before any signs of lameness from
laminitis are observed.
Perhaps, when a horse becomes obese, there is a messenger substance that
promotes or allows for the skin's basement membrane to stretch so the
skin can "enlarge itself" in order to accommodate for the increased
layer of fat under the skin. If this is so, perhaps this same messenger
substance is also recognized by the epithelial laminar basement membrane
in the foot, which would cause the basement membrane to stretch, which
could result in the weakening of the laminae of the foot in the obese
horse. These weakened feet are much more susceptible to grass laminitis
and other predisposing insults known to cause laminitis.
Obese horses need a major change in lifestyle in order to become healthy. Accomplishing this can be a challenging task for the owner because weight reduction in these horses requires a low caloric diet together with a considerable amount of exercise. Many of the horses experiencing laminitis are so sore-footed that much exercise is not possible. Many live lives of constant pain associated with ongoing bouts of laminitis, which finally results in so much damage to the feet that recovery is impossible. These (heavy-type) horses are the most common group associated with the ingestion of grass as a cause of laminitis."