Fresno State's equestrian staff injected two team horses with a tranquilizer just before competitions, the university admitted Wednesday. While the university said it would stop the practice, it was unclear whether any rules were broken.

Veterinarians, coaches and equestrian officials said the effects of the tranquilizer acepromazine (Ace) can vary significantly. Some expressed alarm that riders unknowingly rode horses that had been drugged.

University officials said a minimal dosage was administered and was intended to calm skittish horses.

Two riders on the Fresno State equestrian team told The Bee they saw assistant coach Trista Armstrong inject a team horse named Chelsea with the tranquilizer about 20 minutes before the horse was ridden in warm-ups for a Feb. 21 event.

Rebecca Evans and Katey Augsburger said they were concerned both for the safety of the unknowing riders, who were scheduled to ride a drugged horse, and for the well-being of the horse. "I don't think it's safe for girls to be riding drugged horses," Augsburger said. "It's not fair to the horses or to the girls from other teams who don't know it's happening."

University officials said the drug was used prior to a Nov. 22 competition and again Feb. 21 on the same two horses.

The NCAA has no rulebook for equestrian competition, which is classified as an emerging sport, instead deferring to other governing bodies such as the Intercollegiate Horse Show Association and the United States Equestrian Federation to manage the sport. The Feb. 21 competition was classified as an IHSA event.

The drug is not explicitly forbidden by the IHSA, whose rules regarding drug use state that "care and control of horses including any drugs or medications administered shall be the sole prerogative of the horse provider or their designated representative."

The IHSA does not have the resources to enforce drug rules, said Sophie Rowlands, chairperson of IHSA Zone 8 and the head coach of Cal Poly's equestrian team.

Most governing bodies, however, specifically forbid certain drugs -- including acepromazine -- on the day of competition.

The California Department of Food and Agriculture, which forbids Ace during competitions, might have had jurisdiction over the Fresno State shows. While public horse shows are required to register with the CDFA and are subject to its rules, it isn't certain whether college events fall under the public designation, CDFA spokesman Steve Lyle said.

An attorney for the agency has been asked to review the situation, Lyle added.

According to university officials, Armstrong was acting in conjunction with Fresno State head coach Chuck Smallwood.

Another horse, named Ambience, also was given the drug, university officials said.

Armstrong and Smallwood referred all questions to university officials.

University officials said they conducted an investigation after an athlete voiced her concern about the situation.

"First and foremost, our student-athletes' welfare is our prime concern," said Desiree Reed-Francois, Fresno State's associate athletic director for compliance.

"We felt if our student-athletes are uncomfortable with this, and if it's something we can achieve the same or similar results with alternative methods, we're going to explore those alternative methods."

John Lengel, a veterinarian who is USEF's assistant executive director in charge of drugs and medications, said the effects of Ace "can be anything from subtle to profound" depending on "a number of factors, including dosage amount, the time it was administered, [method] of administration and the condition of the horse."

The university said the dosage was one cubic centimeter or less. At that level, the drug would calm a horse, according to Tim Boone, a staff veterinarian with the CDFA's equine programs.

But Malcolm Hook, a technical delegate for USEF since 1977 and a member of the organization's eventing committee, talked about the dangers of administering such drugs.

"One of them is that not all the horses react to the drug similarly," he said. "Horses already under stress sometimes act not as if they've been tranquilized but as if they were stimulated. As far as I'm concerned, it's not only unethical but also extremely dangerous.

"Why are you putting young women on horses that need to be tranquilized for riders' safety?"

Evans, one of the witnesses, said she noticed that Chelsea's demeanor changed after she was given the drug.

"She was a lot calmer," Evans said. "You could definitely notice the difference. She's dumped riders before, and she didn't so much as buck."

Evans did not, however, think that made the horse safer to ride.

"Hell, no, I would not get on a horse that's been drugged," Evans said. "I liken it to drinking and driving -- it's not a smart idea."

In college competitions, the host school provides horses for all competitors. Horses and riders are paired up through a drawing. The system was set up in order to equalize the playing field as well as reduce travel expenses.

"Regardless of intent, the administration of a tranquilizer is de facto a performance-enhancing thing," Hook said. "It does give someone a competitive edge."

Chelsea can be temperamental and hard to control, according to team members and former coach Megan McGee.

"She was nervous, especially with unfamiliar riders, so she was not as good for competition," McGee said.

Chelsea, a horse donated to the team in 1999, primarily was ridden in practice under McGee. And there were four or five other horses that were used solely for practice because of their unpredictable nature, McGee said. Chelsea was reserved for advanced riders in the open division in non-jumping classes. Ambience was donated to the team in the fall.

"I can tell you categorically that tranquilizers were never used on any horse in my program in competition or practice," McGee said. "It's not safe at all. It's not good for the welfare of the horse. If it had to be tranquilized for a medical reason -- to get sharp edges filed off its teeth or to get treated by a vet -- the horse would not do any activity or practice for the rest of that day and possibly a day after that."

Tranquilizers such as Ace "can remain very active for up to 24 hours," McGee said. "There's never a reason to tranquilize a horse and then expect it to perform."

In fact, McGee said when she was coach there were no tranquilizers available to staff or students.

Sally Batton, the head coach at Dartmouth and a member of the IHSA national board of directors, said no one on her staff is allowed to give a horse a tranquilizer.

"I will not use them, ever," she said. "I will not administer a horse a tranquilizer. If it needs a medical procedure, that's up to the vet. ... If I had a horse that needed to be tranquilized to be ridden, I wouldn't have it as a school horse. All my horses are trained and schooled when I accept them as school horses."

Rowlands, the Cal Poly coach who was at the Feb. 21 competition, said there were no outward signs of horses being drugged. But she added, "If it's the kind of horse that needs Ace, it's not the kind of horse we should maybe even be using. The way the IHSA rules are set up I don't see any evidence of a violation, but we will continue our investigation."