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PURR-go-leyed - Pronunciation guide

Brand Names

  • Heiro Pergolide Powder
  • Permax
  • Prascend Tablets


Rx symbolPergolide, used to treat Parkinson's disease in humans, works by binding with drug receptors that control production of dopamine, which is a chemical neurotransmitter produced by the brain.  

Horses that have clinical signs similar to Cushing's disease in humans have been successfully treated with pergolide since the early 1990's.  The Cushing's-like symptoms are the result of an enlargement or hypertrophy of the horse's pituitary gland.  Pergolide does not cure pituitary pars intermedia dysfunction, but rather helps manage the symptoms, enabling the horse to lead a near-normal life.

As of early 2012,  Boehringer Ingelheim Vetmedica, Inc. received approval from the FDA allowing the sale of PRASCEND® (pergolide mesylate) to veterinarians in the US to treat common signs of PPID (equine Cushing's disease) in horses.


Pergolide is used to treat horses that have pituitary pars intermedia dysfunction, which, essentially, is caused by an enlargement or hypertrophy of the pituitary gland.  This condition is a common problem with older horses and ponies.  Improvement of clinical signs usually occurs after one or two months.

Dosage and Administration

Prescription medicationPergolide
Method Dosage
(click row for calculator)
Concentration Period Duration
Oral1 0.002-0.004 mg/kg 1 mg/tablet   NA


  • 1Do not crush tablets. Provide the dose in the closest 1/2 tablet amount.
  • Federal law restricts this drug to use by or on the order of a licensed veterinarian.
  • Extra-label use of drugs in treating animals is allowable only by licensed veterinarians within the context of a valid veterinarian-client-patient relationship, and does not include drug use in treating animals by the layman (except under the supervision of a licensed veterinarian).
  • The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your equine appears to feel better, the entire treatment plan should be completed to prevent relapse.
  • This medication may be available in forms and concentrations not noted in the above table. Always check the label and literature provided with the medication about the form and concentration and DO NOT USE the calculator if the information differs.
  • Calculator is for educational purposes only. Follow your veterinarian's instructions regarding use of this, or any medication.

Side Effects

Treatment with pergolide may cause loss of appetite in horses. Most cases are mild. Weight loss, lack of energy, and behavioral changes also may be observed. If severe, a temporary dose reduction may be necessary


It is important to identify and use the lowest possible dose.  Over time, the condition in some horses may become resistant to medication.

Use of this drug may interfere with lactation and pergolide should be used in pregnant or lactating animals only if the benefits outweigh the risks.

Pergolide is now FDA approved for use in horses.  It is a prescription drug and federal law restricts this drug to use by or on the lawful written or oral order of a licensed veterinarian.

Pergolide is regulated or prohibited in most sanctioned competitions.  Consult a veterinarian and the individual regulatory group regarding its use in competition horses.


Phenothiazine tranquilizers, such as acepromazine, may interfere with the action of pergolide.


Overdose in humans causes gastrointestinal upset and hallucinations.  No literature is available regarding overdose in horses.


Heiro Pergolide PowderHeiro Pergolide Powder

Prascend Pergolide TabletsPrascend Pergolide Tablets



About the Author

EquiMed Staff

EquiMed staff writers team up to provide articles that require periodic updates based on evolving methods of equine healthcare. Compendia articles, core healthcare topics and more are written and updated as a group effort. Our review process includes an important veterinarian review, helping to assure the content is consistent with the latest understanding from a medical professional.