Harmony Veterinary Services, LLC
Equine Cushings and Metabolic Disorder
Equine Cushings, or Pituitary Pars Intermedia Dysfunction (PPID), and Equine Metabolic Syndrome (insulin resistance) are endocrine (the hormone system) disorders that have become well-known in the last 25 years. Many owners can easily spot the strangely long hair coat (hirsutism) or the excessive crest on an obese pony or Morgan and assume Cushings. But did you know that hirsutism is rarely the first clinical symptom of this disease? Excessive sweating, unusual fat deposits, increased thirst and urination and obesity typically precede a haircoat change. Sometimes these symptoms are caused by Insulin Resistance instead, especially in horses younger than 15 years of age. How confusing! Diagnosis of endocrine disorders relies heavily on clinical suspicion followed by blood tests that unfortunately vary in their sensitivity. A plasma increase in insulin or change in cortisol and ACTH levels differs seasonally. Endocrine levels may in fact be in the normal range even in the face of clinical disease. Treatment of PPID may include oral pergolide, the medication most commonly prescribed as Prascend tablets. Older treatments include cyproheptadine (an antihistamine) or compounded versions of pergolide.
Research is ongoing at the University level to improve diagnosis and treatment success. Endocrine disorders of the horse is a hot topic on Internet chat sites, forums and owner social media pages. Use caution when following unresearched recommendations as some products and feeding protocols can worsen your horses condition.