Also known as Pituitary Pars Intermedia Dysfunction (PPID), is a common endocrine disorder in horses, characterized by an imbalance of hormones in the pituitary gland. It is primarily seen in older horses and is often associated with long, wavy coat (hirsutism), laminitis, and other health issues. The disease is caused by a dysfunction in the pituitary gland, leading to an overproduction of certain hormones, which in turn affects cortisol levels in the body.