DOGS can become canine cannonballs in car crashes, safety experts warns a new safety report.

To prevent man's best friend being a danger in a smash-up, thousands of leaflets about carrying pets safely in cars have been produced by the Royal Society for the Prevention of Accidents.

The leaflet, funded by the Department for Transport, explains how unrestrained pets can be hurt themselves or severely injure people in a car. RoSPA said at 30mph a 50lb border collie would be thrown forward with a force equivalent to nine 12-stone men enough to kill a driver.

Unrestrained pets can distract drivers and cause accidents. After a crash they could escape from the car and be hit or cause collisions. A frightened dog might attack a stranger going to assist an injured driver. The leaflet gives information about safety harnesses, pet carriers, dog guards and travel cages or crates.

RoSPA's road safety project manager Linda Morrison said: "People have been shocked by television advertisements showing a teenager not wearing a seatbelt in a rear seat being flung forward and killing the driver. But they don't seem to realise that the consequences can be just as horrific if a dog is unrestrained in a car."