Officials with the Calgary Stampede said that they're not happy with this year's animal safety record after four horses had to be euthanized during the 2015 event.

The organization is going to look into what can be done in the future to improve animal safety, said Kurt Kadatz, director of corporate communications with the Stampede.

"We're very proud of our Fitness to Compete program, but we're certainly not proud of our safety record this year. It's very disappointing for us as an organization," he told reporters Sunday night.

"We are really going to look hard and find out what we can be doing differently to achieve a better result because we certainly do take it very seriously."

Four horses euthanized in 2015

Kadatz said he believed that in both 2014 and 2013, only one horse had to be euthanized during the Stampede.

On Sunday, a 16-year-old thoroughbred named Ezzy had to be put down after tearing a ligament during a heat of the chuckwagon race. Ezzy was the fourth horse to be euthanized during the Stampede, which wrapped up on Sunday.

Dave Galloway, Ezzy's owner, said the horse will be sorely missed by the entire team.

"I know it's pretty sombre back at our barn right now, and we spend our lives taking care of the lives of these horses, and showcasing them and what they can do," he said, adding that Ezzy loved to race. "He'd be upset in the barn if you didn't saddle him."

Greg Evans, a veterinarian with the Stampede, said Ezzy was examined before the Stampede, as well as each night before the race. There was no indication that the injury was going to happen, he said.

"Even in clinically sound horses, it can occur during racing," Evans said.

Stampede officials say the injury was similar to one that led to another horse being euthanized Saturday, following a heat in the chuckwagon races.

Earlier last week, two other horses had to be put down due to track-related injuries.

Contentious issue

Animal welfare during the Stampede has been a contentious issue for several years.

On Monday, the Vancouver Humane Society called on the public to protest the chuckwagon races, calling them "fundamentally unsafe."

"The Stampede has made endless excuses about the continued loss of chuckwagon horses and has failed to stop these deaths," VHS spokesperson Peter Fricker said in a statement. "People need to let the Stampede know that this is unacceptable."

The VHS has called on the Stampede to suspend the race and set up an expert panel to determine how the race might be made safer.

With files from CTV Calgary