The sudden weekend death of a carriage horse on a cobblestoned Old Montreal street prompted calls Monday for the city to accelerate plans to end the caleche industry.

But the horse's owner said the animal had recently been ill, and he rejected the idea that his workload contributed to his death.

"He wasn't a young horse," Luc Desparois said. "They're big. They're strong like you wouldn't believe, but they still have a fragile heart."

The horse, named Charlot, arrived at Desparois' Lucky Luc Stables last summer. He had shown signs of a minor gastrointestinal pain that took him out of service, but he returned to work Sunday after tests showed nothing wrong.

Charlot collapsed that afternoon as he was pulling passengers through Old Montreal.

"I don't really know (what happened)," Desparois said Monday at his Montreal stable. "From what we know, he just started coughing, and he didn't stop." The coughing spell lasted 15 minutes, and "once he laid down, that was it," Desparois said.

Quebec's Agriculture Department is conducting a necropsy to determine the cause of death.

Desparois said he is eager to know what happened to the horse -- and whether his other 20 horses could be at risk from an infectious disease.

The Montreal administration has already promised to ban caleche rides by the end of 2019, but after Sunday's death there are calls to speed up the process.

"Unfortunately this happened, and it could have been prevented," said Mirella Colalillo, a spokeswoman for an anti-caleche group. She called for an immediate seizure of the horses housed at Desparois' stable.

Montreal Mayor Valerie Plante said the death of Charlot has convinced her more than ever that the caleche industry needs to be shuttered.

"It says to me: 'You made the right decision ... the caleche industry has no place in Montreal anymore,"' she said Monday.

But she said legal considerations and a desire to help caleche drivers transition out of the business mean she is not prepared to advance the Dec. 31, 2019 date.

Plante is awaiting a veterinarian's report on the death but said there is no suggestion the horse was mistreated.

The Montreal branch of the Society for the Prevention of Cruelty to Animals said it sent two investigators to the scene on Sunday. But because the horse was already dead, it was left to provincial authorities to lead the investigation.

Desparois said he would accept compensation and leave the business if he believed caleche rides were harmful to his horses.

"But prove it to me for real, because I do it," he said. "I've been doing it for 33 years, and I don't see a horse unhappy coming to work with me."

Carriage horses have been involved in at least four accidents in Montreal since 2014, and there have been several hundred citizen complaints over their treatment, according to city records.

There were 14 tickets issued in 2016 and 2017 for infractions related to horse health and the state of the carriages.