PPID (equine Cushings disease) is the most common endocrine disorder in horses over 15 years old, causing significant welfare harm that responds well to early diagnosis and treatment.
PPID causes welfare harm through multiple pathways: the physical discomfort of an excessively long, non-shedding coat, the pain of laminitis triggered by elevated insulin and cortisol, and the weakness from muscle wasting that impairs normal movement and thermoregulation. Because PPID is so common in older horses, it is sometimes normalized as aging, delaying diagnosis and treatment. Seasonal ACTH testing during the autumn peak period identifies horses before clinical signs develop, allowing treatment to prevent laminitis rather than manage it after the fact. Horses treated appropriately with pergolide consistently show quality of life improvement that owners describe as transformative, demonstrating the preventable nature of much PPID-related welfare harm.