(E55) Frequency of Endocrine-associated Clinical Signs in Equids with Different Risk Levels for Hyperinsulinemia-associated Laminitis

Background
Recent Equine Endocrinology Group guidelines differentiate risk levels for hyperinsulinemia-associated laminitis (HAL) by insulin level. Understanding the prevalence of different insulin ranges and endocrine-associated clinical signs (EACS) that correlate with an increased risk of HAL aids in successful management of insulin dysregulation.

Hypothesis/Objectives
The objective was to evaluate frequency of EACS with different ranges of insulin values.

Animals
Equids (n=33,941), ages 1 to 45, including miniature donkeys (n=188), ages 3 to 38, with EACS were tested for endocrine disorders by their veterinarian.


Methods
A retrospective analysis was performed on veterinarian-provided data from a 2016-2023 study of equids with suspected endocrine disorders. Equids were considered PPID positive if spring basal, spring post-TRH-stimulated, or fall basal ACTH levels were >35, >110, or >50 pg/mL, respectively, and resting insulin cutoff values were >100 µIU/mL (“HIL”), >45-100 µIU/mL (“MIL”), and 0-45 µIU/mL (“LIL”).

Results
One in four and one in ten equids evaluated had MIL and HIL, respectively, and nearly 58 percent of those equids had PPID. Laminitis and regional adiposity (“RA”) was reported in 40.78 and 43.09 percent in equids with HIL, respectively. In miniature donkeys with HIL, laminitis and RA rates were 63.16 and 78.95 percent, respectively, and RA rates were also elevated in 73.17 percent of miniature donkeys with MIL. Only 38.56 and 15.79 percent of equids and miniature donkeys with HIL, respectively, did not show either laminitis or RA.

Conclusions and Clinical Importance
Practitioners should continue to evaluate insulin levels in equids, despite any absence of RA or laminitis.