Okay, so ACTH is the hormone that tells the adrenal glands (the ones near the kidneys) to produce cortisol. Cortisol is your horse’s natural stress hormone, and a little is fine. A lot? Not so much.
When the pituitary dumps ACTH like confetti, the adrenals go into overdrive. Suddenly, your horse’s body is flooded with cortisol. That’s what causes the potbelly, the laminitis risk, and the weird, shaggy coat.
It’s essentially a thermostat that’s stuck on “full blast.” Your horse isn’t making the cushion—it’s making a hormone mess. And the root cause is that old, tired dopamine factory in the brain.