Caulfield trackwork at first light. Picture: Nicole Garmston Source: News Limited

Rice, in her early 20s, was riding the galloper back to the Aquanita stables after it had worked on the track and had a swim when it became spooked and threw her to the turf.

An ambulance crew at the track treating another woman who had earlier been kicked in the shin by a horse rushed to Rice’s side. She was taken to The Alfred hospital.

Aquanita trainer Stuart Webb said doctors had suggested she would be OK but would not know the full extent of her injuries for the next couple of days.

“Nobody actually saw what happened. She was on the horse and then hit the ground and she was unconscious when we arrived,” he said.

“She remained unconscious and was taken to hospital with head injuries and broken ribs.

“She is in a stable but critical condition and in an induced coma. Doctors will give her all the appropriate tests,” he said.

Her boyfriend and race officials are at her side.

A trackwork rider heads back to the stables. Picture: Ian Currie Source: News Corp Australia

Webb said Rice was travelling Australia with a group of English friends and had ridden at Scone and Randwick among other places.

“She is a good rider and was fully qualified to ride the sort of horse she was on. We don’t know what happened.

“She has been with us for three or four months. She rides work, while a few of her long-time English friends are also employed around Caulfield.

“We have informed her sister (her next of kin contact) and she and her girlfriends are in the hospital with her ... I’m informed little more will be known for the next couple of days.”

Aquanita chief executive Peter Oliver said the team was saddened by the incident and wished the experienced rider a speedy recovery.

“It’s very upsetting for everyone — our thoughts are with her and her family at this time,” he said.

Mr Oliver said an investigation was underway to determine the circumstances surrounding the incident.

The horses make their way through the tunnel at Caulfield track work. Picture: Nicole Garmston Source: News Limited