The California Horse Racing Board (CHRB) has imposed a 15-year suspension and a $567,200 fine on Quarter Horse trainer Monty Arrossa due to five positive tests for carmoterol in 2024. The board determined the banned substance was deliberately given to horses under his supervision. The penalties consist of three-year suspensions for each violation, which will be served consecutively. These violations originated from two post-race and three out-of-competition samples taken from Arrossa’s horses in late 2024.
Carmoterol is a beta-2 agonist and an experimental bronchodilator that has never been approved by the FDA or marketed. Prior to the 2024 spate of positives, the substance had not been detected in horse racing and is classified as a Class 1, Penalty Category A drug under CHRB regulations.
The five positive cases involved three horses—Blood Viper, American Dreamin, and AB Seis Corazones—all owned by Matt and Bindi Dunn’s Dunn Ranch LLC. American Dreamin was linked to three positives, including one following a win in the Grade 1 Golden State Million Futurity at Los Alamitos on October 27, 2024. AB Seis Corazones tested positive after finishing second in the Grade 1 Los Alamitos Super Derby on November 10, 2024. Both horses were later disqualified from these races by Los Alamitos stewards in March 2025, a decision upheld by the CHRB in March 2026 despite Arrossa’s appeal.
In a separate case, the CHRB filed a complaint against Dunn Ranch in January 2026 tied to the same positive tests; hearings took place in April but the case remains unresolved while Dunn Ranch horses continue racing in other states. For Arrossa, hearings held in December 2025 and March 2026, overseen by hearing officer Shauna Weeks Avrith, concluded that accidental contamination was not a plausible explanation for the repeated positive tests.
Avrith stated, “The only reasonable inference from this cluster of positive tests for a banned substance is that someone was administering carmoterol to these horses with the intent to influence the outcome of races.” She also found it credible to infer that Arrossa “at the very least was aware” of the drug’s administration, despite his denial of any knowledge or responsibility and challenges to the lab results.
The ruling highlighted that 10 horses trained by Arrossa were disqualified during 2024 for carmoterol positives. Arrossa claimed ignorance regarding how the substance entered any of the horses, including those involved in the current cases, but Avrith dismissed this testimony as unbelievable given the strong evidence suggesting intentional doping under his care.
One of American Dreamin’s positives was treated differently due to a delay in CHRB’s notification—occurring 34 days post-sample collection instead of the mandated 21 days—meaning the board had to prove by the greater weight of evidence that Arrossa administered or was aware of the drug’s use. Avrith ruled the CHRB satisfied this requirement.
Dr. Jeffrey Blea, equine medical director at UC Davis School of Veterinary Medicine, testified on the difference between American Dreamin’s out-of-competition positive on October 20 and the post-race positive on October 27. He noted the measured quantities suggested intentional dosing and an attempt to adjust the drug level to avoid detection on race day.
Avrith concluded that the CHRB’s evidence collectively supported the inference that carmoterol was administered to American Dreamin by Arrossa or under his direction.
Although the CHRB sought to revoke Arrossa’s license, Avrith determined it lacked proper grounds for license revocation, as Arrossa was only notified about a potential suspension and due procedures for revocation were not followed.
Fines included $268,450 for American Dreamin’s post-race positive (25% of the $1,073,800 Futurity purse), $198,750 for AB Seis Corazones’ positive (25% of the $795,000 Super Derby purse), and additional fines of $25,000, $25,000, and $50,000 for the other three cases.
Since March 2025, Arrossa has not trained any horses, following his suspension by Los Alamitos amid the carmoterol investigation. American Dreamin and AB Seis Corazones have also not raced since the end of 2024, according to Equibase.
This report was initially published by Paulick Report on September 12, 2026, in their News section.
Fan Take: This significant suspension and fine highlight the ongoing battle against doping in horse racing, reinforcing the sport’s commitment to fairness and integrity. For fans, it underscores the seriousness with which regulators will pursue those who jeopardize the welfare of horses and the credibility of racing outcomes.
Source: sports.yahoo.com
