Messara, chairman and owner of Arrowfield Stud, spoke at the American Jockey Club's 67th annual Round Table Conference on Matters Pertaining to Racing at Saratofa in New York on Sunday.
Speakers from all facets of the industry reviewed issues such as animal welfare, fixed-odds betting, television exposure, the application of the interference rule and international stewarding.
At the forefront of each presentation was equine welfare and how to combat an increasingly negative public perception of horse racing that has rocked the American industry.
Joined on stage by the Jockey Club's chief executive Jim Gagliano, Messara offered objective opinions to the big issues and proposed a harmonising of regulations.
"I think that having a national drug policy – a no-drug policy actually – akin to the other jurisdictions in the world would unleash an economic monster here," said Messara.
"Everyone has talked about why people don't want it; well I think that one of the benefits is going to be that the likes of myself will start to look at America again as somewhere to shop for horses.
"As it stands today, it is difficult to judge whether we should be buying a mare in the US. Was she treated with Lasix? Was she on Bute at some stage? What went on?
"Rather than get bitten by it, we stay clear."
Messara added that due to the uncertainty of stallion performance, the foreign perception is that America's credibility as a provider of bloodlines is "low compared to what it could be".
However he did praise the industry infrastructure and called Kentucky the world's most "magnificent breeding ground".
Messara encouraged American horsemen to come together and sign the Horseracing Integrity Act, which he believes will be a "great base for the future" and create a level playing field.
"If you are good enough you will win, but importantly you will become a far more international industry from an economic point-of-view. That will become really valuable for all of those involved," he said.
Hong Kong's chief steward Kim Kelly also spoke and espoused the virtues of applying a global interference rule and recognised international stewarding standards.
The Australian stressed the point of the autonomous interference rule, which infamously changed the result of this year's Kentucky Derby, by presenting delegates with a graphic showing that the vast majority of racing jurisdictions operate under category 1 rules.
The hold-outs are the USA, Canada and Turkey, who compete under Category 2 rules, which Kelly believes "yields inconsistent and undesirable outcomes".
Jockey Club chairman Stuart Janney announced that the Racing Officials Accreditation Program is launching a scheme to send US stewards overseas to gain experience in the professional operation of adjudicating races abroad.
"Horse racing is a sport rich in tradition, but we can and must embrace change. Consensus is not always easily achieved but, when proposed solutions make common sense, it should be," Janney said.
"The programs and initiatives – especially the Horseracing Integrity Act – make all the sense in the world and if indeed we want to become that highly regarded national sport we should embrace positive change; sooner rather than later."
He also revealed a projected North America-registered thoroughbred foal crop in 2020 of 20,500 as well as revising the 2019 foal crop figure from 21,500 to 20,800.