Researchers Evaluate Endocrinopathic Laminitis Prevalence

Laminitis has long been known as a condition in horses that can result from carbohydrate overload, among other causes, but it can also result from endocrine gland dysfunction; this is known as endocrinopathic laminitis. Equine Cushing's disease (also known as pituitary pars intermedia dysfunction, or PPID) and equine metabolic syndrome (EMS) are two conditions that have been linked with endocrinopathic laminitis. According to one group of researchers, this condition might be more common in horses affected by endocrine disease than once believed.

"Despite gastrointestinal and inflammatory forms of laminitis being the focus of laminitis research to date, there is evidence from a large epidemiologic study across the U.S. that these are the least common forms of naturally occurring laminitis reported by horse owners." said Ninja Karikoski, DVM, lead researcher on the study.

Karikoski, who hails from the Equine Teaching Hospital at the University of Helsinki, Finland, Faculty of Veterinary Science, also noted that "endocrinopathic laminitis seems to be more common in certain breeds such as ponies, and it may be somehow hereditary too."

In their study the team evaluated 36 horses with clinical signs of laminitis brought to the university's Equine Teaching Hospital between April 2007 and August 2008. The team's goal was twofold: to determine if endocrine gland dysfunction was present in these horses, and to compare the age, breed, and sex of the laminitic horses with 374 nonlaminitic horses without endocrine disease brought to the hospital during the same period.

They collected blood samples to measure insulin, ACTH (adrenocorticotrophic hormone), and cortisol (commonly known as the stress hormone) levels from the horses presenting clinical signs of laminitis to diagnose an underlying endocrinopathic condition.

Key findings in the study included:

  • Thirty-two of the 36 laminitic horses were affected by PPID or insulin resistance, indicating their laminitis was endocrinopathic in origin;
  • No association was made between sex and diagnosis of endocrinopathic laminitis;
  • Pony breeds made up the largest percent of horses diagnosed with endocrinopathic laminitis; and
  • Endocrinopathic laminitic horses were typically older than the general hospital population.

"Our data support that endocrine testing should be performed on all cases of laminitis that do not have a clear inflammatory or gastrointestinal origin," the team concluded.

The study, "The prevalence of endocrinopathic laminitis among horses presented for laminitis at a first-opinion/referral equine hospital" was published in May 2011 in Domestic Animal Endocrinology. The abstract is available online.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.