Fit to Compete: The FEI's Pergolide Question

Every morning, in barns across Europe and the Americas, a growing number of sport horses receive a single tablet dissolved into their feed. The drug is pergolide mesylate -- marketed as Prascend by Boehringer Ingelheim, and the only FDA-approved treatment for pituitary pars intermedia dysfunction, the neurodegenerative condition still widely known as Cushing's disease. It replaces the dopamine that an aging pituitary gland no longer produces in sufficient quantities. Without it, ACTH levels climb, coats thicken and fail to shed, muscle wastes from the topline down, the immune system falters, and the risk of laminitis rises. With it, for most horses, the clinical picture is managed. The horse works. The horse competes. The horse, by every visible standard, looks well.

Whether it is allowed to keep competing depends entirely on where the next show falls.

At any USEF-sanctioned competition in the United States, a horse with a valid Therapeutic Use Exemption for pergolide competes without restriction -- no drug withdrawal, no competition-day paperwork, no penalty. USEF has permitted this since 1 December 2018. At an FEI-sanctioned international event, the same tablet is a prohibited substance. There is no exemption pathway. The horse must come off the drug before it enters the ring, or it must not enter the ring at all.

That regulatory split is now nearly eight years old. This December, the FEI General Assembly may finally close it.

The current FEI rule protects clean sport. It may be compromising the horse.

A Disease of Aging, Not of Decline

PPID is a progressive neurodegenerative condition of the pituitary gland's pars intermedia -- the most common endocrine disorder of aged equids, according to UC Davis's Center for Equine Health. It is not cancer, not infection, not the consequence of poor management. It is, in the most clinical sense, the endocrine equivalent of aging: a gradual loss of dopaminergic neurons that regulate pituitary hormone output. As dopamine input declines, ACTH production rises unchecked. The downstream effects cascade: abnormal hair growth, muscle atrophy, abnormal fat distribution, excessive sweating, increased susceptibility to infection, and -- most feared -- laminitis.

The condition affects approximately 20 percent of horses over the age of fifteen, a figure broadly consistent across published studies from institutions on both sides of the Atlantic. And critically, it does not respect breed type. A 2025 study published in the journal Animals -- led by Emma Louise Davis, Andrew Douglas Wood, and Julie F. N. Potier at Rossdales Equine Hospital and Liphook Equine Hospital in the UK -- analyzed resting ACTH, insulin, and adiponectin values across 3,935 non-sport and 2,113 sport horse samples. The finding was unambiguous: PPID was as prevalent in sport horses as in non-sport breeds. On follow-up examination, sport horses showed higher median ACTH values and a possible increase in suspected endocrine disorders compared with their non-sport counterparts.

The warmblood competing at 1.40m is not immune. The Grand Prix horse is not immune. The disease does not arrive because the horse has been ridden too hard or managed too poorly. It arrives because the horse has grown older -- and because we have, rightly, learned to keep horses in work longer, and in better condition, than previous generations imagined possible.

The American Precedent

USEF implemented its pergolide TUE policy on 1 December 2018. The system is straightforward: a treating veterinarian submits medical records and PPID-specific diagnostic test results through an electronic medication report form. A three-veterinarian review panel evaluates the submission. If the diagnosis is confirmed, the horse receives a TUE valid for up to three years, renewable with updated diagnostics. The approved horse remains on pergolide at its prescribed dose with no withdrawal before competition and no need to file a medication report at each show.

The policy has now operated for nearly eight years. It has not been revoked or made more restrictive. There has been, instead, a quiet and functional mechanism that allows aged horses with a diagnosed condition to receive a medically necessary treatment without interruption -- and to continue competing at the level their soundness and ability can still sustain.

The significance of this track record should not be understated. When the FEI debates whether to adopt a similar policy, it is not operating in a theoretical vacuum. The American precedent has run. The system works.

Lausanne, March, and the Question on the Table

On 31 March 2026, Session 5 of the FEI Sports Forum in Lausanne -- moderated by FEI Veterinary Committee Chair Jenny Hall -- placed pergolide TUEs on the formal agenda of the federation's veterinary regulations revision. The proposal: allow horses diagnosed with PPID to compete on pergolide under a therapeutic use exemption, ending the current requirement that the drug be withdrawn before international competition.

The rationale is medical. Withdrawing pergolide before competition does not level the playing field -- it destabilizes a managed condition. The horse competes not at some imagined natural baseline, but at a temporary disadvantage created by a deliberate interruption of its treatment. The FEI has acknowledged as much: the current arrangement, in the forum's own framing, means owners "stop giving the treatment to horses before a competition, which could lead to health issues."

But the FEI has also, commendably, refused to treat this as a simple pharmacological question. The forum raised a harder one: "Is a horse that requires medication to maintain its health fit to compete at FEI level?" That question is now the subject of a formal ethical evaluation commissioned by the FEI, led by Professor Madeleine Campbell of the University of Nottingham's School of Veterinary Medicine and Science -- an RCVS Recognised Specialist in Animal Welfare Science, Ethics and Law. The forum also surfaced a clean-sport concern: "questions around enhanced performance have been raised if this is given to horses who don't have the disease."

Nothing was decided in Lausanne; the Sports Forum is a consultative process, not a legislative one. The vote goes to the FEI General Assembly in Jiangyin, China, from 2 to 5 December.

The Steelman Against

The case for keeping pergolide on the FEI's prohibited list is not frivolous, and it deserves a fair hearing. It rests on three pillars.

First, clean-sport integrity. Pergolide is a dopamine agonist. In a healthy horse -- one without PPID -- its effects on pituitary function are pharmacologically real. The concern, raised explicitly at the Lausanne session, is straightforward: if a TUE pathway exists, could pergolide be administered to horses that do not have the disease, under false or borderline diagnostic pretexts, to influence performance? The FEI's clean-sport framework depends on the principle that medications with potential to alter competitive outcomes must be controlled -- and any exemption pathway introduces the possibility of abuse.

Second, the diagnostic threshold. PPID diagnosis relies primarily on resting ACTH measurement and, in equivocal cases, confirmatory testing. These methods produce results on a spectrum. There is no single bright line that separates "affected" from "unaffected." A TUE system that relies on diagnostic testing must grapple with the reality that borderline cases exist, and that financial incentives can, in some contexts, influence which side of the line a case falls on.

Third -- and this is the argument with the most philosophical weight -- if a horse requires daily medication to function normally, there is a legitimate question about whether international competition is the right place for it. Retirement from FEI-level sport is not the same as retirement from life. A horse can be treated, managed, and ridden at home or at the national level without being asked to meet the physical demands of championship competition. Withdrawing from the highest tier of sport to prioritize health is not a failure. It may be the most welfare-forward decision an owner can make.

Where the Argument Breaks

Each of these objections is reasonable in principle. Each weakens under scrutiny.

On abuse potential: USEF's experience is instructive. The three-veterinarian review panel has operated for nearly eight years without the policy being revoked or tightened. The diagnostic criteria for PPID are well established, the testing is specific, and the TUE must be renewed with fresh diagnostics. No system is immune to bad actors, but the sustained functioning of a major national federation's TUE program across nearly a decade suggests the risk is manageable -- and managed.

On diagnostic uncertainty: the same argument could be made about any medical condition for which a TUE might be granted. The existence of borderline cases does not invalidate the diagnosis itself. Veterinary medicine routinely makes clinical decisions on spectrums. A robust review process -- particularly one that includes endocrinology expertise and requires confirmatory testing -- can handle grey areas without abandoning the principle of exemption.

On fitness to compete: this is where the current rule undermines its own logic. Under the FEI's existing framework, a PPID-affected horse that withdraws from pergolide before competition is permitted to compete -- less stable, less well, at greater risk. A PPID-affected horse that remains on pergolide, clinically managed and presenting no outward sign of disease, is prohibited. The rule does not ask whether the horse is fit. It asks whether the horse is medicated. Those are not the same question, and conflating them produces an outcome in which the welfare result is worse for the horse whose owner follows the rules.

A rule that forces a horse off its medication to prove it is healthy is not a welfare standard. It is a bureaucratic contradiction.

December in Jiangyin

The FEI General Assembly convenes in Jiangyin, China, from 2 to 5 December. The veterinary regulations revision -- including the pergolide TUE proposal -- is expected on the agenda. Nothing was decided in Lausanne; the Sports Forum is a consultative process, not a legislative one. The ethical evaluation by Professor Campbell and her specialist colleagues will inform the final proposal. The national federations will vote.

For the owner of a fifteen-year-old warmblood who has been quietly managing a PPID diagnosis while the horse continues to produce clean rounds at the national level, the stakes of that vote are concrete. A TUE pathway would mean the horse's international career does not end because of a treatable, manageable, non-communicable condition. The absence of one means the horse is permanently retired from international sport the moment it receives a diagnosis -- or, worse, that the owner delays diagnosis to preserve competitive eligibility, a perverse incentive the current rule creates and the current rule cannot prevent.

The FEI has earned credit for putting this question into the open -- for commissioning an ethical review rather than simply rubber-stamping or refusing. That process should be allowed to run. But the editorial position here is clear: when a well-established treatment for a common age-related condition carries no credible evidence of performance-enhancement abuse, when a nearly eight-year national precedent has demonstrated that a TUE system can function with integrity, and when the alternative is a rule that makes horses less healthy in order to comply, the welfare argument is not ambiguous.

The sport asks horses to give their best. The least it can do is allow them to take their medicine.