Police are investigating a spate of slashing attacks on horses at a North Yorkshire stables.
Vallar was slashed under the chin, sustaining nerve damage
A 15-year-old thoroughbred eventing horse suffered a six-inch (152mm) cut under its chin early on Friday morning.
Two weeks ago, a mare at the stables in Great Ouseburn, near Boroughbridge, was found with a deep cut on her right ear.
Shortly before that another mare was whipped across the chest as she grazed in a field. Police said the owner was "devastated by the appalling attacks".
A North Yorkshire Police spokesman said the injured eventing horse, Vallar, may be unable to take part in competitions again as a result of nerve damage.
Officers have joined forces with the RSPCA to investigate the attacks, which all took place at night.
"They are also concerned for other horses in the area and will be increasing patrols," the force spokesman said.
Anyone with information is urged to contact the police immediately.