Authorities say a Pierce County sheriff's deputy has been hospitalized after his patrol vehicle struck four cows that had wandered into the middle of the road in Roy.

The News Tribune reports that the 29-year-old deputy, who has not been identified, was knocked unconscious after the Sunday night incident and treated at a hospital for a concussion.

Sheriff's office spokesman Ed Troyer says the deputy had been responding to a traffic accident when his SUV struck the cattle, which had escaped from a nearby farm.

Three cows died from the impact and one was euthanized.

Officials have not determined whether the cows' owner will be held responsible for the incident.