What is PPID?

Pituitary Pars Intermedia Dysfunction (PPID), also known as Equine Cushing’s Disease, is an endocrine disorder of the pituitary gland, resulting in hormonal imbalances.  It is most commonly diagnosed in middle-aged and geriatric horses.


What are the clinical signs of PPID?

  • Long/wavy haircoat (also known as hirsutism)
  • Abnormal shedding patterns
  • Excessive sweating or lack of sweating (also known as anhydrosis)
  • Lethargy
  • Poor athletic performance
  • Chronic recurrent laminitis
  • Infertility
  • Weight loss
  • Muscle wasting, especially along the topline
  • Abnormal fat distribution along crest of neck, tail head, sheath, and above the eyes
  • Increased consumption of water and increased urine output
  • Delayed wound healing
  • Increased susceptibility to infections


How is PPID diagnosed?

If outward clinical signs indicate you horse may have PPID, your vet will likely recommend bloodwork to confirm diagnosis.  The most common method of diagnosing PPID is by measuring ACTH levels in blood plasma.  If plasma ACTH levels are greater than the normal reference range, it is a good indicator of PPID.  However, ACTH concentrations naturally rise in the fall for horses in the northern hemisphere, therefore the reference range should be adjusted accordingly when testing horses in the fall months.


How is PPID managed?

Diet: The basis for feeding horses with PPID is low starch and higher fats.

Grain: Several commercially produced feeds are available, including SafeChoice Special care and Purina Wellsolve L/S.  These should only be used to supplement calories needed to maintain an appropriate body condition.

Forage: Lower quality hay is best. Sugar-rich grasses should be avoided.  This is worst with new grasses in the springtime.  Turnout should also be avoided later in the afternoon or at dusk as this is when grasses are more sugar-rich. Grazing muzzles can be worn to slow down forage intake.

Exercise: For horses not currently experiencing a bout of laminitis, a regular exercise program should be used to encourage appropriate body condition.  Please consult with your veterinarian on the appropriate regimen for your horse.

Medications: Prascend (pergolide) is commonly prescribed to horses with PPID to regulate plasma ACTH levels. Learn more about Prascend.

Regular veterinary visits are recommended to identify subtle or early progressive signs of disease.

Initially, bloodwork should be checked frequently. Once your horse’s PPID is more controlled, bloodwork should be rechecked at least yearly to confirm that your horse is still being appropriately managed on their medication.


For more information about PPID and other equine metabolic disorders, visit the AAEP website.