Senior Sergeant Anthony Bond, of Dunedin, said police were called to the Waikouaiti-Waitati Rd (State Highway 1) near Evansdale after reports of a car hitting an animal, at about 8.45pm on Friday night.
A vehicle driven by a 55-year-old woman, with an 8-year-old boy in the passenger seat, was heading north on the highway when a cattle beast walked into their path, Snr Sgt Bond said.
"That's had no time to stop, so it's hit the cattle beast, killing it."
They crashed into a ditch on the side of the road.
The dead cattle beast was then pushed into the southbound lane, into the path of another vehicle driven by a 65-year-old man with a 75-year-old passenger.
"And they've hit the dead cattle beast.
"That vehicle overturned and slid on its roof for several metres before coming to a stop in the southern lane."
A 38-year-old man driving a third vehicle, who was following the second, slammed on the brakes in an attempt to avoid the dead cattle beast.
He instead clipped a second cattle beast which then ran off.
The first two of the three vehicles were "severely damaged", Snr Sgt Bond said.
A Hato Hone St John spokesperson said two ambulances and an operations manager attended the scene.
Four patients, two in moderate conditions and two in minor conditions, were transported to Dunedin Hospital.
Snr Sgt Bond said tow trucks had been used in the past to remove dead cattle beasts that were obstructing roads.
"It’s literally a dead weight."
Police were also called to reports of a truck hitting a deer, also on the Waikouaiti-Waitati Rd, at 10.45pm on Saturday.
The deer had strayed onto the road and was struck by a southbound truck, killing it instantly, Snr Sgt Bond said.
The truck remained in the middle of the road, several other vehicles stopping behind it.
But one car that attempted to avoid the stationary truck instead drove into a barrier, glancing it.
The truck was undamaged and left the scene, while the car had already driven away, Snr Sgt Bond said.
