Equine Cushings Disease: Pituitary Pars Intermedia Dysfunction and Welfare

Pituitary pars intermedia dysfunction is a common endocrine disease in older horses causing significant welfare impact when undiagnosed or untreated.

Key Facts

PPID, commonly called equine Cushings disease, affects an estimated 15 to 25 percent of horses over age 15.
It is caused by dysfunction of the intermediate lobe of the pituitary gland, leading to cortisol dysregulation.
Classic signs include a long, curly coat that fails to shed, muscle wasting, and increased water consumption.
Laminitis is the most serious welfare complication of PPID, affecting up to 70 percent of diagnosed horses.
Diagnosis is confirmed through autumn ACTH blood sampling, as seasonal physiological rise affects interpretation.
Pergolide mesylate is the standard and effective medical treatment for managing PPID.
Treated horses can live comfortably for years with appropriate management and monitoring.

Welfare Considerations

PPID imposes substantial welfare burdens when unrecognised or inadequately treated. Horses with untreated PPID experience chronic discomfort from laminitis, recurrent infections due to immune suppression, and muscle wastage affecting ability to perform normal postures and movement. The long abnormal coat causes overheating in warm weather and prevents effective grooming by the horse. Many cases go undiagnosed because the gradual onset of signs is attributed to normal ageing. Autumn ACTH testing for all horses over 15 years is recommended by equine welfare organisations as a proactive screening approach. Treatment is effective and affordable relative to the welfare return achieved.

What You Can Do

Request autumn ACTH testing for horses over 15 years as part of annual health screening.
Recognise coat abnormalities, muscle wasting, and increased drinking as PPID warning signs.
Implement dietary management alongside medication to reduce laminitis risk in PPID horses.
Monitor treated horses regularly for dose adjustment needs as the disease progresses.
Clip heavy coats in warm seasons to prevent heat stress in affected horses.