Support for horse racing among its most ardent fans suffered a “massive” drop in confidence this year, under concerns about the integrity of the sport’s participants and the safety of its horses, according to a professional marketer who has conducted 10,000 interviews with racing fans over the past five years.

Jonathan Chavez, the co-founder of a marketing company that has been paid by the National Thoroughbred Racing Association to survey horse racing fans over the past five years, said that numbers measuring the confidence of hard-core racing fans dropped 12 to 13 points in the last year, according to his surveys. Chavez said the drop was the most dramatic he had seen in his years conducting the surveys.

“[Racing] may have reached a tipping point,” Chavez said.

As an analogy to horse racing’s problems this year, Chavez cited the widespread loss of confidence in the sport of boxing over the past 20 years because of concerns about integrity.

According to the surveys, racing fans said they were most concerned about the “overmedication” of horses and the perception that the bet-processing system was being manipulated. Chavez also cited high-profile ontrack breakdowns that have marred the Triple Crown and Breeders’ Cup over the past few years, as well Big Brown’s last-place finish in the Belmont Stakes after being hyped as a kind of superhorse going into the third leg of the Triple Crown.

Chavez made his comments during an afternoon panel discussion examining racing’s public-perception problems on the opening day of the University of Arizona’s Symposium on Racing in Tucson, Ariz. The annual event opened on Tuesday and runs through Thursday.

Marsha Kelly, the president of Kelly Media Consulting, said that the loss of confidence in racing was making the sport vulnerable to attack from animal-welfare organizations that were eager to exploit bad news in the industry to further their own goals. Kelly has advised the fur industry in the past on how to protect their businesses from attacks from animal-rights organizations, and is currently advising the greyhound racing industry.

“They don’t go after people eating hamburgers,” Kelly said about animal-welfare organizations. “That’s a tough sell. They go after low-hanging fruit: small industries, with small fan bases, facing economic duress. [Racing] is low-hanging fruit.”

Kelly said that racing needs to form political coalitions with other agriculture-based and animal-use industries in order to protect its business. She said that a recent referendum in Massachusetts, in which voters overwhelmingly passed a measure banning greyhound racing in the state, was an indication that parimutuel sports need to act now to address public-perception problems, principally by acting aggressively to address any animal-welfare issues.

“The public does not expect perfection,” Kelly said. “They want you to make a good-faith effort, and they want you to be committed to that effort.”