A DOG, a deer, a lorry, a motorbike and three cars were caught up in a chain reaction that left hundreds of motorists trapped on the A419.
Police traffic officers were called to remove the carcasses of a greyhound-type dog and a deer that had met a nasty end on the dual carriageway, between the Turnpike roundabout and the Stratton St Margaret exit, on Saturday.
But a lorry driver travelling southbound did not spot the police car in the road until the last minute.
Braking hard and swerving out of the patrol car's way, the lorry hit a car, which in turn knocked a motorcyclist off his bike.
The motorcyclist was taken to hospital with a leg injury, but his condition was not thought to be serious.
At least two more cars shunted into each other in the pile-up.
Sgt Richard Day said: "Police attended the A419 to remove the carcass of a dog and a deer from the road.
"Police were in attendance when a lorry driver was driving along and did not notice the police car in the road.
"He braked suddenly, the car behind went into his back and a motorcyclist was hit by a car.
"The motorcyclist had a suspected fracture to his leg and was taken to hospital."
Hundreds of motorists were stationary for up to two-and-a-half hours on the section of road between the Turnpike roundabout and the scene of the accident, directly beneath the Kingsdown Road bridge.
Traffic officers tried to ease drivers' frustration by turning cars at the back of the queue around to ease the flow.
PC Steve Love, of Wiltshire Police's northern roads police unit, said: "We closed the southbound carriageway shortly after the collision, but there were a lot of vehicles trapped in the stationary traffic."
The road was reopened at about 2.15 pm.
Residents in the area said deer lived in the Kingsdown woods and were often seen in the area.
Jeremy Lambert, of Kingsdown Road, who was walking his black Labrador near the scene shortly after the accident, said: "A lot of people walk their dogs in the woods beside the road. You often see deer there and my dog even chases them a bit."
There was also an accident on the northbound carriageway of the A419, just before 6.30pm on Saturday evening, involving two vehicles.
l Police, fire and ambulance were called to an accident at the Salthrop crossroads near the Science Museum on Friday at about 10.45am.
The road was closed for more than an hour while recovery of the vehicles involved took place.