The collision happened just before midnight on Saturday.
A teenager is in hospital after suffering serious injuries after his car collided with a loose horse on the M8 in Co Tipperary.
Gardaí were alerted to a serious road traffic collision on the M8 at Cahir Abbey Upper just before midnight on Saturday 16th July.
A horse broke out and got onto the motorway and a vehicle collided with it.
The male driver, in his late teens, sustained serious injuries and was taken to Cork University Hospital.
Gardaí are appealing for witnesses to come forward.

Kfm Recruiting for Advertising Sales Dept.
Further Increase Expected In Number Of Landlords Leaving Property Market, As Price Of Three-Bed Semi Rises In Kildare
Over 1,700 Garda Checkpoints In Operation Over Christmas Period, With Naas RPU Detecting Multiple Speeding Motorists
€1.2m Approved For Zipline And High Ropes Adventure Centre At Donadea
Christmas Appeal To Adopt Dogs As Euthanasia Figures Rise
Speed Enforcement To Increase In Kildare With 21 New Camera Zones To Be Rolled Out In January
Over 400 Motorists Caught Speeding So Far Today, Including A Driver In Kilcock
Transport Minister In Discussions With Irish Rail About Extending Late-Night Trains Beyond Christmas