Novel tulobuterol positive leads to summary suspension in New Mexico racing

The New Mexico Racing Commission issued a summary suspension to owner-trainer Julian Rey Honesto after a post-race test from Nov. 2, 2025 detected tulobuterol in the Quarter Horse Easy Winner. Regulators characterize tulobuterol as a long-acting beta-2 agonist bronchodilator that is not FDA-approved for use in the United States and is classified as a prohibited substance under HISA and by several international racing authorities. Racing officials believe this may be the first confirmed U.S. positive for tulobuterol in a racehorse.

Laboratory reporting originated with an industrial testing lab that flagged the compound in the post-race sample. The commission moved quickly to impose a summary suspension, a process that removes the trainer’s license and prevents horses under that license from competing while the case is adjudicated. A subsequent hearing upheld the immediate suspension; a disciplinary hearing to determine final penalties is pending. Because summary suspensions are generally reciprocally enforced across jurisdictions, the action will likely affect Honesto’s ability to race horses in other states and associations.

Tulobuterol’s pharmacology makes it especially sensitive in short-distance racing. In addition to bronchodilation that can ease breathing, beta-2 agonists have repartitioning effects that can increase lean muscle and reduce fat—effects that have performance relevance for sprint races. Testing experts cited by regulators say modern laboratory methods can detect tulobuterol at low concentrations and that the compound is available in some markets despite not being approved for veterinary use in the U.S. Those factors increase both the detectability and the enforcement challenge for regulatory labs.

The case sharpens existing concerns in Quarter Horse racing where short sprints magnify any drug-related speed advantage. For racing communities focused on integrity and fair competition, the presence of a novel or non‑approved bronchodilator raises questions about stable medication controls, supply chains, and the need for targeted testing panels. It also underscores the role of industrial and official labs in identifying uncommon substances and the regulatory mechanics that follow a positive finding.

What this means for trainers, owners, and racing officials is practical and immediate: review stable medication protocols, tighten recordkeeping and chain-of-custody procedures, and consult your veterinarian and legal counsel if you face testing irregularities. Expect sharper scrutiny in sprint divisions and potential reciprocal suspensions if a regulator acts first. Our two cents? Treat this as a wake-up call—tighten controls now and keep thorough, dated records so a single test doesn’t snowball into a career-changing suspension.