A breakthrough in laminitis research by a team of scientists at University of Queensland, Australia, and colleagues, was published in August 2007 The Veterinary Journal. The study explains an important link in sugar and starches as causes for laminitis.
Laminitis was induced in healthy, lean, young ponies by prolonged (up to 72 hours) administration of insulin via euglycemic clamp. This procedure maintains blood glucose at a set level, eliminating involvement of glucose toxicity. Prior to the study, all ponies’ insulin levels were in normal range. In addition to clinical observation of lameness, examination of hoof tissues after euthanasia confirmed laminitis in all four feet. There was no evidence of gastrointestinal involvement.
This is the author’s 11-year-old mixed breed pony mare taken the day of her last insulin test, after grazing for only two hours. Her insulin tested 3.5 times normal. One month earlier on a diet of only low sugar hay, her insulin was within normal levels. She has had laminitis several times in the past, although she was sound throughout this period. Note she is not overweight.
While insulin resistance has long been associated with laminitis, researchers have only speculated as to the causative agent. Some have suggested that inflammatory substances released as a consequence of obesity were to blame. This new research points the finger at the toxic aspects of insulin, although the mechanism by which it causes l