Cushings Disease (Pituitary Pars Intermedia Dysfunction – PPID)

Cushings Disease (PPID) causes the horse’s pituitary gland to function abnormally and secrete hormones which control the horse’s metabolism at an abnormal level.

Can occur in horses of all ages but more common in the older horse, occurs in all breeds and both male and female horses.

Often early clinical signs of Cushings Disease (PPID) go unnoticed by owners and it is not until the disease is advanced that testing is performed.

Clinical signs include:

  • long hairy coat
  • delayed coat shedding / decreased shedding
  • lethargy
  • decreased athletic performance
  • laminitis
  • cresty neck, fatty bulges above eyes and on top of tail
  • abnormal sweating (increased or decreased)
  • increased drinking / urinating
  • pot belly
  • weight loss
  • muscle loss
  • recurrent infections
  • poor reproductive performance

Diagnosis is by clinical examination and usually a simple blood test is performed.

In some instances a dexamethasone suppression test will need to be performed which involves two blood samples taken approximately 19 hours apart after administration of a cortisone medication by injection.

Treatment is with daily Pergolide Mesylate which is available in an oral liquid or tablet form

Initially treatment many cause a loss of appetite, weight loss and a lack of energy and the dose rate may need varying according to each individual horse’s response.

There is no “cure” for Equine Cushings Disease as it is a chronic disease which requires daily treatment to manage.

Early treatment can minimise progression of the disease and allow affected horses to live normal lives

In some instances where the disease is minor in severity no treatment may be required apart from careful nutritional management

Diet is an important part of managing a Cushing’s horse and it is recommended low GI feeds such as speedibeet, rice bran oil products and adequate roughage are fed, and that energy content of the diet is minimised.

It is also important to supplement the horse’s diet with an electrolyte replacer that includes adequate quantities of magnesium.

Metabolic Syndrome and Insulin Resistance are two other common conditions which may cause similar symptoms.