Horse Cushings Disease: Long-Term Welfare Management of PPID

Pituitary pars intermedia dysfunction (PPID or equine Cushings disease) is a progressive neurological condition affecting an estimated 15-25% of horses over 15 years old, with significant welfare implications if unmanaged.

Key Facts

PPID results from pars intermedia dysfunction causing excess ACTH and cortisol production, disrupting multiple body systems
Clinical signs include hypertrichosis (long curly coat that fails to shed), muscle wasting, laminitis, and increased water intake
Laminitis in horses with PPID is particularly severe and difficult to manage, often leading to euthanasia
Pergolide mesylate (Prascend) is an effective medical treatment that improves clinical signs in most horses
Early diagnosis using resting ACTH measurement or thyrotropin-releasing hormone stimulation testing enables earlier treatment
Seasonal fluctuation in ACTH levels (highest in autumn) means testing during this period may improve diagnosis sensitivity
Horses with well-managed PPID can maintain acceptable quality of life for years with appropriate treatment and monitoring
Dietary management including low-sugar forage and restricted grazing is essential alongside medical treatment

Welfare Considerations

PPID welfare management is a domain where early diagnosis and systematic treatment produce profoundly different outcomes than missed diagnosis or delayed treatment. Horses with undiagnosed PPID may suffer for extended periods from the consequences of uncontrolled cortisol excess: repeated laminitis episodes causing intense foot pain, progressive muscle wasting reducing mobility and comfort, and immune suppression increasing infection susceptibility. Once diagnosed, pergolide treatment typically produces measurable improvement in clinical signs within weeks — shedding returns, energy improves, and laminitis frequency decreases. The welfare argument for proactive PPID screening in horses over 15 years is strong: ACTH testing is straightforward, and early treatment initiated before severe clinical signs develop produces substantially better long-term welfare outcomes than treatment begun after significant deterioration.

What You Can Do

Schedule annual ACTH testing for horses over 15 years old, ideally in late summer when seasonal ACTH elevation aids diagnosis
Learn to recognize early PPID signs including subtle coat changes and muscle loss along the topline
Manage diet carefully in PPID horses — low-sugar, low-fructan forage and restricted grazing reduce laminitis risk
Maintain veterinary monitoring every 3-6 months for horses on pergolide to assess dose adequacy
Consult an equine internal medicine specialist for complex PPID cases with severe laminitis or management challenges
Support research into PPID pathophysiology and novel treatment options for horses who respond poorly to standard therapy