Predicting Laminitis in Ponies

What would you give to know with certainty whether your horse or pony one day will be affected by laminitis?

If you’re like most horse owners, you may be willing to part with a pretty penny to keep laminitis at bay. Australian researchers recently investigated the frequency of dietary-induced laminitis as it relates to insulin dysregulation, adrenocorticotropic hormone (ACTH) concentrations, and clinical signs of pituitary pars intermedia dysfunction (PPID)*.

Thirty-seven mixed-breed ponies participated in the study. Researchers determined insulin dysregulation by using an oral glucose test, and ACTH concentrations were measured through blood samples. Clinical signs of PPID were noted, including changes in hair coat, muscle-wasting, appearance of fat pads or unusual fat distribution, overconsumption of water, and excessive urination.

“Whereas laminitis occurred in all five ponies with clinical signs of PPID, in ponies with elevated ACTH but no clinical signs of PPID, the frequency of laminitis was lower and was not different to that in ponies with normal ACTH,” the researchers reported. “Interestingly, the maximum insulin response in ponies who developed laminitis was similar regardless of group: ponies with normal ACTH and laminitis had a concentration of 295 µIU/mL, compared to those with elevated ACTH and laminitis of 342 µIU/mL, and to those with clinical signs of PPID and laminitis of 494 µIU/mL. In contrast, the ponies who did not develop laminitis had a maximum insulin concentration of 173 µIU/mL, significantly lower in comparison to the combined laminitis group’s concentration of 366 µIU/mL.”

While the study revealed that ACTH concentrations alone cannot forecast laminitis risk, when considered in conjunction with the clinical signs of PPID, incidence of laminitis could be predicted in this group of ponies with complete accuracy.

The take-home message, according to the researchers, is “to identify PPID horses at risk for laminitis, an oral carbohydrate test to detect insulin dysregulation and a clinical examination is strongly recommended.”

If you suspect your horse or pony of having a metabolic condition, consult a veterinarian for an individual treatment plan.

Managing laminitis-prone horses often begins with conscientious feeding management and an exercise program if soundness allows. The nutrition consultants at Kentucky Equine Research are available to help devise a feeding program that is best for your horse.

In-depth feeding guidelines are available in the booklet Nutritional Management of Metabolic Diseases, assembled by the health-care team at Kentucky Equine Research.

*Meier, A.D., M.A. De Laat, D.B. Reiche, and M.N. Sillence, 2018. Predicting laminitis in insulin-dysregulated ponies with suspected pituitary pars intermedia dysfunction: The importance of clinical examination. In: Proc. Australasian Equine Science Symposium 7:22.