A study published in the September issue of Veterinary Pathology suggests that laminitis may not be the sudden-onset illness we tend to imagine.
Researchers from Finland, Australia, and the United Kingdom worked together to document cases of 14 laminitic horses and ponies with high insulin levels in their blood (known to be a common precursor to laminitis). Specifically, researchers looked at the lesions inside the lamellae — the soft, interlocking finger-like projections that hold the hard outer hoof capsule onto the internal structures of the hoof.
What they found was a bit counter-intuitive: after rating the severity of the lesions, researchers could find no correlation with the length of time the horses had been reported to be suffering from symptoms of the illness and the time the lesions were forming in the feet. In fact, in several cases, the lesions must have been beginning before the horses showed the first signs of discomfort.
“It is more than likely that horses with endocrinopathic laminitis have ‘mini-episodes’ of laminitis before acute laminitis, which the owners either can’t or don’t see because the signs are so mild,” says study author Dr. Ninja Karikoski, clinical teacher of equine internal medicine at the University of Helsinki.
Karikoski said this finding applies to one type of laminitis. There are two types — endocrinopathic and inflammatory. Inflammatory laminitis takes place as the result of an inflammation somewhere else in the body, like colitis (intestinal inflammation) or metritis (uterine inflammation). It’s typically quick to develop and progresses rapidly with severe symptoms. Endocrine-related laminitis, on the other hand, is connected with a hormonal disease like equine metabolic syndrome or Equine Cushing’s disease (PPID). Endocrine laminitis cases are usually chronic, developing gradually and sticking around for the long haul.
“If an endocrinopathic disease is picked before full blown laminitis,” Karikoski says, “laminitis may be prevented by treating the underlying hormonal problem.”