Treating Laminitis in Horses: Approaches to Diagnosis

With each passing year, researchers learn more about laminitis in horses, specifically the influences of endocrine irregularities on the development of the disease. Endocrinopathic laminitis is associated with pars pituitary intermedia dysfunction, metabolic syndrome, and insulin dysregulation. But veterinarians—with their frantic, often relentless, schedules—may find it impossible to stay informed of every nuance discovered by researchers. A recent study evaluated how vets diagnose endocrinopathic laminitis in the field, looking closely at whether new research findings are used.^*

For this study, researchers at Louisiana State University created an online questionnaire that featured two sections: (1) four demographic questions centered on the education and professional lives of the respondents, and (2) 14 questions that pertained to cases in which systemic laminitis was suspected but with no clinical signs of illness. A link to the survey ran for three months in an equine-specific veterinary e-newsletter, and the survey was posted on two social media sites during the same timeframe.

Researchers collected 214 usable responses: 142 from equine-only ambulatory or referral hospital vets, 58 mixed-practice vets, and 14 other vets (academia, research, racetrack work, etc.).

How frequently did these vets evaluate cases of laminitis each week? Just over half (55%) estimated they saw less than one case per week, while 28% guessed they evaluated one case a week. The remainder assessed more than one case per week.

Depending on their age, many practitioners indicated they have changed their diagnostic approach since graduating from veterinary school, including greater use of diagnostic testing for underlying endocrine or metabolic disease. Ninety-three percent of respondents reported running one or more diagnostic tests in suspected cases of  laminitis. Veterinarians measured basal adrenocorticotropin (ACTH) more frequently than basal insulin, and dynamic tests of ACTH and insulin were more likely to occur on reexamination as opposed to first call.

In addition to ACTH and insulin measurement, other tests were performed less frequently, including venography and measurement of serum amyloid A, leptin, thyroxine, glucose, and iron.

When asked about the factors that influenced changes in diagnostic approach, respondents indicated personal experience, continuing education activities, and evidence-based medicine or research.

According to the researchers, “diagnosis of endocrinopathy was reported to be important to outcomes and treatment strategies, and improved discussions with owners about management and prognosis.”

Horses diagnosed with endocrinopathic laminitis must often receive care from multiple specialists, including vets, farriers, and nutritionists. From a day-to-day management perspective, nutritional countermeasures may help keep horses from developing more severe disease or flare-ups.

Dietary management often focuses on restricting intake of nonstructural carbohydrates, namely sugars, starches, and fructans,” said Kathleen Crandell, Ph.D., a nutritionist with Kentucky Equine Research. “The consumption of these particular carbohydrates can increase the risk of laminitis through hyperinsulinemia or hindgut disturbances in laminitis-prone horses.”

Horses with metabolic conditions are often fed diets composed of carefully selected forages. All-forage diets do not provide all of the vitamins and minerals necessary for optimal health. Consider a high-quality vitamin and mineral supplement to round out the diet.

If faced with a laminitic horse and you’re unsure where to turn in terms of nutritional advice, consult a nutritionist.

^*Rumfola, E., H.E. Banse, M. Atkins, C.M. McGowan, and J.L. Ireland. 2022. Approaches to endocrinopathic laminitis in the field: Results of a survey of veterinary practitioners in North America. Journal of Equine Veterinary Science 110:103856.

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