Associations among beta-endorphin, ACTH, cortisol concentration, age, and clinical signs indicative of pituitary pars intermedia dysfunction in geriatric horses

In this geriatric study cohort, haircoat abnormalities were associated with increased β-END and ACTH concentrations, whereas other clinical signs, such as muscle atrophy, weight loss, and lethargy, were primarily linked to age. Because PPID is diagnosed based on clinical signs and ACTH concentrations, it is important to distinguish clinical signs that are age-related from those associated with PPID.