Horse Cushings Disease: Welfare and Long-Term Management

Understanding pituitary pars intermedia dysfunction (PPID, Cushings disease) in horses — the most common endocrine disease in older horses — its welfare implications and evidence-based management.

Key Facts

PPID affects approximately 21% of horses over 15 years old and 30% of horses over 30 years old
The condition results from loss of dopaminergic inhibition of the pituitary pars intermedia, causing excessive hormone secretion
Hypertrichosis (abnormal coat retention) is the most visible clinical sign but PPID causes systemic effects including laminitis susceptibility, muscle wasting, and immune suppression
Pergolide mesylate (Prascend) is an effective treatment that reduces clinical signs in 70-80% of affected horses when maintained at appropriate dosage
PPID-associated laminitis is the most serious welfare complication — proactive management of affected horses during high-risk periods prevents many episodes
Seasonal variability in ACTH levels creates a predictable autumn period of elevated laminitis risk in PPID horses requiring management adjustment

Welfare Considerations

PPID represents a highly manageable chronic disease when diagnosed early and treated appropriately, yet continues to cause significant preventable welfare harm through late diagnosis and inadequate management. Horses with untreated PPID experience progressive immune suppression, weight loss, and laminitis risk — all significantly impairing quality of life. The welfare case for regular PPID screening of horses over 15 years old is strong: early treatment significantly reduces the laminitis risk that represents the most serious welfare complication of the disease. Horses maintained on appropriate pergolide therapy with careful nutritional management can maintain excellent quality of life for years after diagnosis, demonstrating that PPID is a disease of management opportunity rather than inevitable welfare decline.

What You Can Do

Screen horses over 15 years old annually for PPID using ACTH measurement — ideally during spring when baseline is lowest
Initiate pergolide therapy promptly on PPID diagnosis rather than waiting for severe clinical signs
Implement laminitis prevention protocols for PPID horses during the autumn ACTH surge period — restricted grazing, low-NSC diet, and close monitoring
Work with your veterinarian to titrate pergolide dosage to the minimum effective level — regular ACTH monitoring guides dose optimization
Learn to recognize PPID clinical signs beyond hypertrichosis — muscle wasting, weight loss, and increased drinking may precede obvious coat changes