SAN DIEGO -- First it was Barbaro, the 2006 Kentucky Derby winner who shattered his right hind leg.

Then came Eight Belles, who fractured her front ankles at the 2008 Kentucky Derby.

Both horses had to be put down due to their injuries.

It was the catastrophic breakdowns of Barbaro and Eight Belles that has sparked a renewed debate on the treatment of race horses.

Animal rights activists like Christina Tacoronti said there is a dark side to the industry.

"Up to three horses everyday are killed in the U.S. due to horse-related injuries," said Tacoronti. "The industry puts speed and profit well above the safety of the horses."

Contrary to what some believe, many said horses are treated very well.

"I mean, you have an investment in a horse. These horses can cost millions of dollars. You're going to treat them better than you''' probably treat your children," said Joe Harper of Del Mar Race Tracks.

The back-and-forth debate has dogged the industry for decades.

In an exclusive 10News/Survey USA poll, San Diegans were asked about how they felt about the sport. The poll showed 77 percent believed horse racing should be allowed, while 15 percent said it should be banned.

The poll was disappointing news for Tacoronti, who said racing is inhumane.

"They are drugged right before the race to mask injury and they are manipulated to go faster," said Tacoronti.

According to the 10News poll, however, 65 percent of San Diegans believed race horses are treated humanely.

Harper said horses are born to run.

"When you look at the horse running around the race track, the horse is doing what he wants to do," said Harper.

Many have applauded Del Mar trainers and owners for their treatment of horses.

More than 60 percent of San Diegans polled gave owners and trainers an A or B grade for the way they treat their horses.

The Del Mar Race Track has recently installed they new polytrack, a new surface made of sand, rubber and wax.

"Last year, we saw a 70 percent reduction in the fatalities out there on the synthetic course, and hopefully it will continue," said Harper.

Harper also said the majority of owners and trainers put their horse's health first.

However, he said there are some who try to cheat.

"The kind of the money that's involved in racing these days, there's going to be people that take a shot at doing something illegal," said Harper.

While the deaths of Barbaro and Eight Belles showed just how fragile horses are, it also placed a spotlight on the use of drugs in horse racing.

"The question implies that people intentionally medicate to mask conditions and then run it to the extent that it does exist. Its the exception rather than the rule," said Drew Couto of the Thoroughbred Owners of California.

Despite reassurance from owners, some people believe horses are given drugs to hide injury.

"There are some drugs that are being used that are banned in many states, but are still being used in horse racing to mask the signs of injury and also to make the horses race faster," said Tacoronti.

In July, California banned the use of steroids in horse racing.

The 10News poll showed about 70 percent of San Diegans believed trainers use illegal performance-enhancing drugs on horses.

Many in the racing industry agreed that there is a problem when it comes to the use of illegal drugs, but they said only a small percentage break the rules.

California Horse Racing Board equine medical director Dr. Rick Arthur said the state has very stringent testing.

"If anything, the biggest complaint of the testing is that it is too sensitive. Most Little Leaguers could not pass a post-race test we do in California," said Arthur.

Arthur said the state tests for drugs down to the part per billion (ppb).

The testing makes it difficult for some trainers who use legal drugs therapeutically.

Trainer Howard Zucker said even a very small amount of any drug will show up.

"The public needs to realize that our livelihood is at stake. There's not that much cheating; its more accidental, minor overages of day-to-day (dosages) and what's therapeutic and allowable," said Zucker.

Some point to the need for a universal program to help resolve the concern.

Richard Shapiro of the California Horse Racing Board said, "What the industry needs is one central body of government to establish rules that are uniform throughout the industry and I think that would lead to better environment dealing with drugs, track safety and other different issues."

Some said those issues are what gives horse racing a bad rap.