Suddenly, according to police and witnesses, Dutch became startled and trotted the carriage into the intersection, striking cars westbound on Callowhill.
The driver, whom Kates identified only by her first name, Molly, was thrown from the carriage onto a windshield, and rushed to Hahnemann Hospital with possible head injuries, police said.
She was feeling much better Saturday afternoon, said Kates, who said he had visited Molly in the hospital
"She is doing great and in good spirits," Kates said. "All of the tests, they all came back negative. She has some lacerations and scars, but, she's more concerned about the horse than anything else."
Dutch, a 9-year-old Draft Horse suffered leg damage, said Kates, but is expected to survive.
"He's in vet care and he was eating and putting weight on the leg, which are both good signs," Kates said.No other people were hurt, police said.
Dutch has been with the company for three years, Kates said, and before Friday has never been involved in an accident.
Police were able to corral the animal within a block of the accident.
"He's truly a docile animal that doesn't typically spook," Kates said. "And it's odd to think he would run through that intersection. He's been at that intersection a thousand times."
Kates would not say how long the driver has been with the company and said he was waiting for police accident investigation officers to complete their review.
No one is expected to be charged in the collision, police said.
In April 2010, three people were injured when a car struck a horse carriage from behind at a traffic light near Independence Hall, causing one carriage to collide with two others. Two of the drivers were flung from their carriages and suffered head injuries.
In 1999, two carriages collided near Fourth and Market, ejecting some passengers, but hurting no one. In that incident, police believed the horse was spooked by a passing truck.
And in 1987, James Dewan, 51, of Olney, suffered severe head trauma when the carriage he was driving for the Ben Franklin Carriage Company was struck by a hit-and-run vehicle near Delaware Avenue and Race Street
In response to Friday's accident, the Philadelphia-based Peace Advocacy Network, a group that strives for "the absence of violence in the lives of people and animals," said it will be holding a July 22 protest between Chestnut and Market Streets, calling for a ban on all horse-drawn carriages.
Contact staff writer Mike Newall at 215-854-2759, mnewall@phillynews.com, or @MikeNewall on Twitter.