Horse Racing Law

Representation & Consultation

The Practice

Administrative Hearings
We specialize in the representation of owners, trainers, jockeys, drivers, and other licensees at hearings before Boards of Stewards, State Racing Boards and Commissions, and Administrative Law Judges.
Writs and Appeals
If you have received an adverse decision, we are experienced in appealing administrative decisions to the courts, including Courts of Appeal and Supreme Courts.
General Equine Practice
We assist our clients with general equine legal services including the formation of business entities, partnerships, syndicates, and various equine business contracts.
Our goal is to provide the highest quality legal services
in a professional and determined manner.

About Us

Darrell Vienna is renowned for his efforts on behalf of horsemen throughout the racing world having represented or assisted horsemen in Arkansas, Arizona, California, Delaware, Florida, Kentucky, New Mexico, Massachusetts, New York, Texas, Great Britain, Hong Kong, and Singapore.  His efforts have resulted in numerous acquittals for licensees charged with violations of racing regulations.

A graduate of the University of California and Loyola Law School, Mr. Vienna has been practicing equine law for over two decades.  That experience has allowed him to establish strong networking relationships with leading equine practitioners across the nation.  Clients can be assured of vigorous and well-coordinated representation based on experience and know-how.

Mr. Vienna has been licensed as a thoroughbred trainer in 25 racing jurisdictions.  During his training career, his horses earned over $50,000,000 and he saddled more than 1,200 winners, including 68 graded stakes winners.
Mr. Vienna was elected as officer and director of the California Horsemen’s Benevolent and Protective Association and the California Thoroughbred Trainers.  He has served as a contract consultant to the California Horse Racing Board tasked with reviewing the agency’s regulatory framework and streamlining its administrative hearings.  He has successfully litigated matters against racing commissions and racetracks.  He has also consulted on Standardbred and Quarter Horse matters as well.

Given his background, education, and accomplishments, Mr. Vienna is regarded as a preeminent authority in equine law and all aspects of horse racing, regardless of breed or jurisdiction.
 We provide clear and simple advice ensuring that you fully understand
all the options so we can together make a balanced decision on how to proceed.




​​We are experienced in appealing decisions in administrative cases to the courts through a process called Petition for Writ of Administrative Mandamus.

We are veterans at administrative hearings before Boards of Stewards, State Racing Boards and Commissions

We appeal judgments from Racing Commissions and Superior Court decisions to the Court of Appeal and the Supreme Court.
Ex Parte Applications

We offer representation in actions to persuade the Superior Court to stay an agency's order from taking effect.
Consultation & Expert Witness

We are available to consult with legal counsel in equine law cases and have been qualified as expert in equine appraisal, race track procedures, and horse racing custom and practice.
General Equine Law

We are skilled in the preparation of equine agreements, livestock liens, partnerships, LLC formation, purchase and sales and civil litigation for damages.  We are also knowledgeable in the drafting and interpretation of Horse Racing Law and Regulations.

Verdicts & Results

Verdicts & Results

Trainer Exonerated
Class 1 Violation-Morphine

Trainer Acquitted
Class 3 Violations

​​​Court of Appeal Overturns Sanctions - Clenbuterol

Trainer exonerated on all charges for alleged violation of Trainer Insurer Rule involving morphine.

CHRB v. Robert Frankel

Trainer acquitted on charge for alleged violation of Trainer Insurer Rule involving phenylpropanolamine.

CHRB v. Gary Jones

In a published opinion, California Court of Appeal set aside revocation of Trainer’s license and fine of $160,000.

De La Torre v. CHRB (Cal. App. 2017)

Suspension of Jockey Overturned on Appeal

DNA Test Resulted in
Dismissal of Charges

Trainer Exonerated
Class 2 Violations-Lidocaine

Steward’s suspension of jockey for riding rule infraction overturned on appeal to State Racing Board.

CHRB v. Victor Espinoza
Complaint dismissed after DNA test proved official sample was not collected from Trainer’s horse.

CHRB v. Desormeaux
Trainer acquitted of violation upon findings of lidocaine by Massachusetts State Racing Commission.

Mass. Racing Comm. v. McCooey

Petition Granted
Against Horse Racing Board

Substantial Reduction
in Suspension

Jockey License Reinstated Following Fitness Hearing​​

Petition submitted to Office of Administrative Law challenging California Horse Racing Board medication regulation resulted in determination that regulation was invalid.

2015 OAL Determination No. 6
Following an appeal before the Delaware Racing Commission, a 1-year suspension for a class 1 substance (strychnine) violation was reduced to 1 month.

Mareno v. Delaware Board of Stewards
Presumption of unfitness of Jockey based upon reciprocity with Singapore, a foreign racing jurisdiction, was rebutted and Jockey’s license reinstated in U.S. racing jurisdiction.

In the Matter of David Flores, CHRB

Order of Finish 
​Decision Reversed

Racing Board
Withdraws Invalid Procedures

Superior Court Rules Against
​Horse Racing Board

Reversal of Oaklawn Board of Stewards’ failure to disqualify runner in Apple Blossom Hcp. resulted in change of order of finish and redistribution of purse.

Tanaka v. Oaklawn Park Stewards
Horse Racing Board withdraws Governing Procedures for Hearings following petition to Office of Administrative Law challenging regulation.

OAL: CTU 2016-1017-001
Los Angeles Superior Court rules California Horse Racing Board violated its own rules by allowing Racing Association to disqualify horses by hair testing.

Gustavo De La Torre v. CHRB

Owner Awarded Purse on Reversal of Stewards' Decision

Court Reverses Denial of Transporter's License

Racing Board Forced to Withdraw Invalid Directive

Reversal of Stewards’ decision to disqualify runner from win resulted in change of order of finish and redistribution of purse.

In the Matter of China Girl Lover
Superior Court overturns CHRB license denial for failure to comply with mandatory legal duty statutes.

 (Acted as Consultant to attorney, Carlo Fisco, Esq.) 

Lockwood v. CHRB
Following submission of Petition to Office of Administrative Law, CHRB withdraws invalid directive regarding license denials based on criminal convictions.

 (Acted as Consultant to attorney, Carlo Fisco, Esq.) 

OAL: CTU 2014-1422-001

Racing Board Agrees not to Enforce Veterinary Directive

Jockey Suspension Overturned on Appeal

Purse Redistribution Reversed
by State Racing Board

CHRB agrees to withdraw veterinary directive following submission of petition of Office of Administrative Law challenging directive as underground regulation.

OAL: CTU 2017-0123-01
Steward’s suspension of jockey for riding rule infraction (alleged failure to ride mount to finish) overturned on appeal to State Racing Board.

CHRB v. Corey Nakatani
September, 2018

Reversal of Steward's Decision to redistribute purse over owner license issue.

In the Matter of Nicholas Cafarchiai
CHRB, September, 2018