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Combatting Performance-Enhancing Drugs In Horse Racing

Last updated: October 17, 2023

By: Miles HenryFact Checked

Recently, I had the opportunity to attend the quarterly meeting of the Louisiana Horse Racing Commission. It was pretty wild. The room was full of trainers whose horses failed drug tests. Some were first-time offenders, but many had been caught multiple times. The high number of repeat offenders was alarming.

Performance-enhancing drugs (PEDs) are substances that are used to enhance athletic performance. The most common PEDs for racehorses are anabolic steroids, blood-doping agents, and stimulants. These drugs are used to increase muscle mass, oxygen-carrying capacity, and endurance but can cause serious health problems in horses.

In this blog post, we’ll delve into the types of performance-enhancing drugs in horse racing and which are common, how PED use has evolved over time in the sport, the steps being taken to address drug use, and the ongoing challenges and potential solutions to this issue.

The history of PED use in horse racing

Performance-enhancing drugs in horse racing is not a new phenomenon. In fact, the use of PEDs in horse racing dates back to the sport’s early days. In 1897, The Jockey Club, a group of wealthy horse owners, introduced a rule to stop the practice of “doping” horses.

People using drugs to make horses run better in races has been around for a while, and the people in charge of horse racing have been trying to stop it for just about as long.

In the sport’s early days, the primary focus was on preventing the use of stimulants and opiates, such as cocaine, strychnine, and morphine, which were commonly used to “dope” horses and improve their performance.

Picture of a horse race from the 1800s.

In the late 19th century, The Jockey Club, a group of wealthy horse owners, introduced a rule to end this practice. However, the main motivation for this rule wasn’t to protect the horses’ health but to ensure fair competition for the large sums of money being wagered on races.

As the sport grew in popularity and more money was wagered on races, efforts to prevent PED use became more formalized. By the 1940s, most horse racing tracks had implemented testing protocols to detect the use of performance-enhancing drugs in horses.

These protocols typically involved testing saliva and urine samples from horses before and after races. These testing methods were not as sophisticated as today’s methods, but they detected the most commonly used PEDs at the time.

However, as the sport of horse racing evolved, so did the PEDs used. In the 1960s and 1970s, anabolic steroids began to be used in horse racing. This was followed by the use of blood-doping agents in the 1980s and 1990s.

It’s important to note that, through the years, as new drugs have emerged and as technology has improved, testing protocols have evolved and become more sophisticated. Today, many governing bodies have implemented strict testing protocols to detect performance-enhancing drugs and take appropriate action against those who violate the rules.

One of the most notable instances of PED use in horse racing occurred in 2021, the Kentucky Derby winner Medina Spirit was found to have had a prohibited substance in its system, and its trainer Bob Baffert was suspended for 90 days and fined $7,500 by the Kentucky Horse Racing Commission.

This led to the horse’s disqualification and named Mandaloun the 2021 Kentucky Derby winner. This incident brought the issue of performance-enhancing drug use in horse racing to the forefront and led to increased efforts to combat the use of performance-enhancing drugs in the sport.

In another high-profile case, in 2020, the United States Southern District of New York indicted 27 trainers for using PEDs on their horses.

Picture of performance-enhancing drugs in horse racing.

Types of Performance-Enhancing Drugs used in horse racing

When it comes to performance-enhancing drugs (PEDs) given to racehorses, there are three main categories: those that increase energy and alertness (stimulants), those that relieve pain and inflammation (pain relievers), and those that affect the horse’s respiratory system (pulmonary drugs).

These drugs are used to make horses run faster or stronger in races, but their use is illegal and can harm the horse’s health, compromise the integrity of the sport, and lead to penalties for trainers, owners, and their associates.

Here are some examples of drugs that fall into each of the three categories of performance-enhancing drugs (PEDs) commonly given to racehorses:

  1. Stimulants: Examples include caffeine, theobromine, and amphetamines.
  2. Pain relievers: Examples include non-steroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone, flunixin, and ketoprofen.
  3. Pulmonary drugs: Examples include bronchodilators, such as clenbuterol and albuterol, which open the airways in the lungs, making it easier for the horse to breathe.

It’s important to note that many of these drugs have serious negative side effects, and their use is illegal in horse racing. Additionally, many racing organizations have strict rules against using performance-enhancing drugs, and trainers who are found to be using them can face significant penalties, including fines and suspensions.

Anabolic steroids

Anabolic steroids are the most commonly used performance-enhancing drugs in horse racing. These substances are designed to increase muscle mass, strength, and endurance. These drugs are synthetic versions of the male hormone testosterone, which can help horses to perform better by improving their endurance and overall physical condition.

They can also help to mask injuries and other conditions that would otherwise affect a horse’s performance. Steroids can be administered in different ways, such as oral, intramuscular, intravenous, and transdermal.

Some common anabolic steroids that have been used in horse racing include Stanozolol, Nandrolone, Boldenone, and Trenbolone, all synthetic steroids that are similar to testosterone and known for their ability to increase muscle mass and strength.

Using anabolic steroids in horse racing is illegal in many countries and can lead to penalties for trainers, owners, and other individuals involved in the sport. Additionally, using anabolic steroids can harm the horse’s health and compromise the integrity of the sport.

Here is a YouTube video critical of the lenient treatment of Bob Baffert for his long misuse of drugs in horse racing.

YouTube video

Other performance-enhancing drugs

Blood doping agents

Blood-doping agents are also used in horse racing. These substances are designed to increase the number of red blood cells in a horse, which can increase oxygen-carrying capacity and improve performance. Blood doping can also lead to serious health problems, including heart failure and stroke.


Diuretics are a performance-enhancing drugs that can be used in horse racing to help horses lose weight and improve their performance. They work by increasing the amount of urine the horse produces, which can help remove excess fluid from the body.

This can help horses to run faster and perform better by reducing their weight and making them less fatigued. Diuretics can cause dehydration, electrolyte imbalances, and other harmful effects on the horse’s health and can be dangerous in high doses.

Additionally, their use can mask other underlying health issues and compromise the integrity of the sport by giving an unfair advantage to the horse using it.

Furosemide (also known as Lasix) is the most commonly used diuretic in horse racing and is used to treat a condition called exercise-induced pulmonary hemorrhage (EIPH) in horses.

EIPH is a condition where the horse’s lungs bleed during intense exercise, and it can be caused by a number of factors, such as overworked lungs, high altitude, or genetic predisposition.

Furosemide works by reducing the amount of blood that enters the lungs during exercise, which can help to reduce the severity of EIPH and improve the horse’s performance. The use of furosemide in the treatment of EIPH is a controversial topic.

While it is considered to be an effective treatment for EIPH, it has also been banned in some countries and racing organizations because of concerns over its potential performance-enhancing effects and the potential masking of other performance-enhancing drugs.

Additionally, furosemide can also negatively affect the horse’s health, and its use should be under the guidance of a veterinarian. It’s worth noting that furosemide is regulated by many racing organizations, and it is typically only allowed to be used on horses diagnosed with EIPH by a veterinarian.

Picture of a quarter horse.
Racing quarter horse

Zilpaterol, the new drug in quarter horse racing

When I was at the racing commission meeting, Zilpaterol was the drug most trainers were caught using, and each worked with quarter horses. Zilpaterol is a drug that promotes muscle growth and strength in animals, particularly cattle and horses.

Zilpaterol improves the horse’s performance in quarter horse racing by increasing muscle mass and strength. This can help the horse run faster and perform better. But it can also cause health issues. I spoke to an LSU vet about Zilpaterol, and he explained that this drug causes severe damage and that horses given it are likely to die within two years.

Current efforts to combat PED use in horse racing

Racing commissions and organizations are at the forefront of efforts to combat PED use in horse racing. These organizations have implemented strict rules and regulations regarding PED use in horse racing. They also conduct testing and detection of performance-enhancing drugs in horses.

Testing and detection methods have also been improved over the years. Today, horses are tested after races to detect the presence of PEDs. Advanced laboratory techniques and technology have made detecting performance-enhancing drugs in horses easier.

Penalties for PED use in horse racing are severe. Horses that test positive for performance-enhancing drugs are disqualified, and their trainers are suspended. At the racing commission I attended, some racehorse trainers were handed down suspensions of five years.

In addition, owners of horses that test positive for PEDs may be fined and lose their racing privileges. Education and outreach programs are also important aspects of efforts to combat PED use in horse racing.

These programs aim to educate trainers, owners, and other stakeholders about the dangers of performance-enhancing drugs and the importance of maintaining the integrity of the sport.

Picture of one horse running much faster and suspected of using performance-enhancing drugs.

Challenges in combatting PED use in horse racing

One of the major challenges in combatting PED use in horse racing is the constantly evolving PEDs and detection methods. As PEDs become more sophisticated, it becomes more difficult to detect them.

This makes it essential for racing commissions and organizations to stay up-to-date with the latest performance-enhancing drugs and detection methods. International regulations also present a challenge in combatting PED use in horse racing.

Horse racing is a global sport, and different countries have different regulations regarding PED use. This makes it difficult to ensure that all horses competing in international races are free of PEDs.

Public perception is also an important reason to combat PED use in horse racing. The public expects horse racing to be a fair and honest sport, and using PEDs undermines this expectation. Maintaining public trust in the sport is essential to ensuring all horses are free of performance-enhancing drugs.


PED use in horse racing is a serious problem that can have negative effects on the horse’s health and the integrity of the sport. Racing commissions and organizations, along with other stakeholders, have implemented strict rules and regulations, testing and detection methods, penalties, education, and outreach programs to combat PED use in horse racing.

However, the constantly evolving performance-enhancing drugs and detection methods, international regulations, and public perception remain challenging. It is crucial to continue efforts to combat PED use in horse racing to maintain the integrity and trust of the sport.

Picture of performance-enhancing drugs.