Summary: New research, conducted in collaboration with the British horse feed company SPILLERS®, has shown that the equine diet, and more specifically, a starch rich food, can influence adrenocorticotropin hormone ,or ‘ACTH’, test results. This could potentially lead to an incorrect disease diagnosis in some horses when ACTH is used to test for Pituitary Pars Intermedia Dysfunction (PPID).
Key point: The threshold values for diagnosis of the disease currently vary dependent on the season, but these new findings suggest that diet should also be considered.
Hoof Blog note: Laminitis in older horses is commonly blamed on PPID, but a definitive diagnosis by hormonal test results is required to determine if an underlying endocrine condition is the cause of laminitis. Some horses with PPID may lose weight, which might lead owners to increase feed or change to a higher-starch diet to counter weight loss. Horse owners and veterinarians should communicate about a horse's feed intake before testing; future research may reveal more specific guidelines about how feed type influences test results.
