A newly obtained USDA report alleges that a clandestine injectable spread equine infectious anemia through contaminated needles and likely contained the novel beta agonist behind multiple high-profile Quarter Horse trainer cases.

By Chelsea Hackbarth, The Paulick Report

PAULICK REPORT–JULY 16, 2026–A newly obtained U.S. Department of Agriculture epidemiological report concludes that investigators believe a clandestine injectable performance-enhancing substance referred to as "Robinson’s juice" likely served as both the vehicle that spread a 2024 outbreak of equine infectious anemia (EIA) and the source of the novel beta agonist carmoterol that triggered still-pending regulatory cases against some of Quarter Horse racing’s most successful trainers.

The report provides the first detailed account explaining the connection between the unprecedented EIA outbreak and the equally unprecedented rash of carmoterol positives that have roiled Quarter Horse racing for nearly two years. It alleges that Robinson’s juice – a closely guarded injectable distributed through a small network of horsemen – was administered to racehorses for years as a performance enhancer before contaminated needles turned one bottle into the source of an EIA outbreak that ultimately killed or led to the euthanasia of at least 25 horses.

The investigation also concludes that carmoterol, a potent beta agonist not approved for use in the United States, was likely one component of Robinson’s juice. Five of the horses that tested positive for carmoterol in New Mexico were trained by Heath Taylor, and all five were also among the EIA-positive horses. The remaining seven positives came from the barn of Toby Keeton, who investigators described as another known user of Robinson’s juice, albeit from a separate bottle that was not believed to have become contaminated with the EIA virus.

The USDA report helps connect a series of events that, until now, had largely appeared to be separate investigations. After the EIA outbreak emerged in the fall of 2024, federal animal health investigators began tracing the source of the infections in an effort to determine how the disease had spread, identify at-risk animals and prevent future outbreaks. The investigation ultimately appears to have provided racing regulators with information that led to the first known U.S. cases involving carmoterol. The Quarter Horse industry has since seen multiple leading trainers suspended, millions of dollars in purse money withheld, and regulatory proceedings stretching into a second year.

Robinson’s juice, according to the USDA report, "has been concocted since at least 2014 by the Robinsons in Oklahoma, a father-son team of former horse trainer and veterinarian who have tightly controlled distribution channels where only certain individuals are given access to the substance for racing performance-enhancing purposes."

The Robinson family has previously been linked to medication-related enforcement actions. Former trainer R.L. "Rick" Robinson is the father of veterinarian Dr. Justin Robinson, who in 2018 was indicted on eight charges of influencing a race outcome in Bexar County District Court in Texas. Robinson was named as the attending veterinarian in connection with a series of Class 1 positive drug tests from horses trained by then-reigning AQHA champion trainer Judd Kearl and two others. The drug detected was nomifensine, an antidepressant that has not been legal in the U.S. since the 1980s. Kearl was suspended a total of 19 years by the Texas Racing Commission. Trainers Jose Sanchez and Brian Stroud were suspended for four years and one year, respectively.

In 2023, in connection with the above indictments, Dr. Robinson was given a $500 fine and probation under a deferred adjudication agreement. His Texas veterinary license was also suspended for five years, from Feb. 8, 2023.

ccording to the USDA report: "Robinson’s juice reportedly comes as a liquid injectable in 250 mL bottles with the intended horse receiving 0.5 mL intramuscularly per day for a series of days before the race and then stopping administration of the substance about 2 days before the race."

The connection to Heath Taylor’s horses allegedly occurred through Sammy Valeriano, owner of 11 of the 25 EIA-affected horses and, according to the USDA report, "a confirmed unsanctioned (bushtrack) racing participant."

"When [Valeriano] sends his horses to a trainer for sanctioned racing, he sends a specific groom or grooms to accompany those horses," the report states. "The groom reportedly is the only person who is allowed possession and administration of Robinson’s juice to Valeriano’s horses at sanctioned racetracks. It is hypothesized that Valeriano’s groom may also help other trainer’s/owner’s/groom’s horses either under direction or at his own discretion by also giving Robinson’s juice to those horses before their races. The mechanism of payment for the Robinson’s juice back to the Robinsons is reportedly a percentage of the earnings for each of the races won by the horses receiving the product."

The report posits that Valeriano’s groom administers Robinson’s juice by "hurriedly going from stall to stall, often at night and in the dark, and sometimes is reported to not even use a halter to restrain the horse for the quick injection of the small 0.5 mL dose. In this attempt to avoid detection, the same needle and syringe is used between horses to draw up the small dose, inject, then dip back into the bottle to inject directly into the next horse quickly, which is an absence of sterile technique guaranteeing blood contamination of the bottle of Robinson’s juice."

Investigators concluded that this practice would have continually introduced infected blood into the large, 500-dose bottle of Robinson’s juice. As horses began to get sick, the viral load would have increased in the bottle, thereby reinfecting the horses with each dose.

This method of disease transmission is referred to as iatrogenic. Investigators concluded this was the only plausible explanation for so many EIA positives in such a short span of time. Natural fly bites, the other known method of transmission for EIA, have been shown to take decades for large numbers of horses in the herd to all become infected.

"The very small amount of infected blood capable of being transferred via the fly’s mouthparts, estimated at 0.0001 mL, can transmit only a miniscule amount of EIA virus," the report explains. "In comparison, the amount of blood on the tip of a needle after use is estimated at up to 0.1 mL of blood capable of transmitting significantly more virus by iatrogenic means if EIA virus is present."

There is no cure for EIA, and under U.S. law, infected horses must be euthanized or kept 200 yards away from other equids for the remainder of their lives. The disease is endemic in Mexico; there are no regulations to mitigate the spread.

As the USDA’s investigation into the EIA cases progressed, information about Robinson’s juice was shared with state racing officials.

Earlier this year, Racing Medication & Testing Consortium executive director Dr. Michael Hardy told the Association of Racing Commissioners International conference that state racing investigators had confiscated a performance-enhancing product, which ultimately allowed laboratories to develop the first validated method for detecting carmoterol in equine blood, urine, and hair.

"A couple of years ago, a state racing authority investigator reached out to the RMTC," Dr. Hardy relayed. "They had confiscated a particular product, they had intelligence around how it was being used, and what they thought was the likely class of medication. We were able to direct that testing, which ultimately resulted in the detection of carmoterol in that contraband. As a result of that, the laboratories were able to develop a detection methodology to identify carmoterol in an equine biological sample. As a result of that, the laboratories are now capable of detecting it in blood, urine, and hair, which essentially resulted in the detection findings in late 2024 and 2025 in California, New Mexico, and Texas."

The USDA report does not explicitly identify that confiscated product referenced by Hardy, but it does state that the New Mexico Racing Commission submitted the blood (serum) samples from all horses racing on Sept. 2, 2024, All-American Futurity Day, for additional drug testing.

On Feb. 12, 2025, the NMRC held a press conference announcing the findings of carmoterol in samples from 12 horses sent for this additional drug screening. Carmoterol is a beta-agonist performance-enhancing drug not approved by the FDA for use in the United States.

Five of the horses with carmoterol findings were trained by Heath Taylor; all five were also EIA-positive.

The remaining seven horses that tested positive for carmoterol were trained by Toby Keeton, who also had carmoterol findings announced by the Texas Racing Commission two weeks prior to New Mexico’s announcement.

"According to informants, Keeton was also a known and prolific user of Robinson’s juice, although he would have been using a bottle acquired separately and not associated with Valeriano’s groom in Heath Taylor’s string," the USDA report explains. "Clearly Keeton’s bottle of Robinson’s juice had not become contaminated with EIA virus, and all of his horses have been EIA-negative to date. The carmoterol findings, coupled with the known use of Robinson’s juice in both trainers’ racing strings, indicate that at least one drug component in Robinson’s juice is likely carmoterol, although other as-yet-undetermined drugs may also be part of the concoction."

The carmoterol findings ultimately expanded beyond Taylor and Keeton. In the months that followed, multiple top-10 Quarter Horse trainers faced suspensions and regulatory proceedings after horses in their care tested positive for the previously unknown substance.

Keeton was summarily suspended in New Mexico and, after 22 of his horses tested positive for carmoterol in Texas, received a 64-year suspension and $535,000 fine from the Texas Racing Commission. His New Mexico proceedings remain pending due to legal challenges over split-sample testing, while his Texas disciplinary action is also being challenged.

Taylor was summarily suspended by the New Mexico Racing Commission following the Feb. 12, 2025, announcement of the five carmoterol findings from his barn. Similar to Keeton, Taylor’s cases are awaiting the results of legal challenges over split-sample testing. According to Equibase records, he has not started a horse since Feb. 2, 2025.

California trainer Monty Arrossa also had several horses test positive for carmoterol, including G1 Los Alamitos Two Million Futurity winner Favorite Cartel Jess. The CHRB has officially charged Arrossa with five medication violations for carmoterol; a hearing on those charges took place March 4-5, 2026, and the CHRB is awaiting the hearing officer’s proposed decision.

Arrossa has not started a horse since March 3, 2025; he was "banned from training" at Los Alamitos by track management on March 16, 2025.

By mid-2025, the cases had reached five of the AQHA’s top 10 trainers by 2024 earnings. Along with Keeton (No. 1), Taylor (No. 3) and Arrossa (No. 6), Juan Diaz Jr. (No. 2) was summarily suspended in Texas and New Mexico over multiple alleged carmoterol positives, while Jeremy Derozin (No. 10) received a one-year suspension in Louisiana after two horses tested positive for the drug.

Despite being repeatedly identified throughout the USDA report, Sammy Valeriano’s owner licenses remain active in California, New Mexico, and Oklahoma. His Valeriano Racing Stables owns three Grade 1 winners in 2026 alone, including last weekend’s Rainbow Futurity winner, El Huracano V, and the Rainbow Oaks winner, Toby Sis. The stable has won 19 of 49 starts this year with earnings of $1,927,251.

Asked about the USDA report’s allegations involving Valeriano, California Horse Racing Board Executive Director Scott Chaney told the Paulick Report: "We don’t comment on pending investigations. The CHRB finds the contents of the USDA report troubling."

The USDA report does not address the pending regulatory cases. Instead, it provides the first explanation for how the novel substance may have entered Quarter Horse racing and why the earliest wave of positives centered on two barns already linked by the federal investigation into the 2024 EIA outbreak.

The USDA document, obtained by the Paulick Report via Freedom of Information Act request, is the first known government account describing the alleged distribution network, the proposed mechanism by which the disease spread, and investigators’ conclusion that the clandestine injectable likely contained carmoterol.

Reposted with permission of PaulickrReport.com.

* * * * * * * * * * * * * * * *

Would you like more industry news delivered directly to your inbox? Click here to sign up.