By Maddy Biddulph Farmers are urging dog walkers to stop pets from attacking young lambs -- and warning they may shoot to protect livestock.

Marilyn Ivings, chairman of the National Farmers' Union in Berkshire, Buckinghamshire and Oxfordshire, said: "The NFU has already received reports of dogs maiming sheep which eventually died from their injuries or were destroyed by a vet to put them out of their misery.

"For this reason, the NFU is reminding people to keep their dogs on a lead near livestock."

Thousands of sheep and cattle die as a result of injuries caused by dogs every year.

The union says livestock worrying has a considerable financial impact on the industry, costing about £2m per year.

Mrs Ivings, who farms beef cattle, poultry and cereals at Church Enstone, near Chipping Norton, said: "Owners forget that the friendly family pet can turn wolf.

"But they should remember that the law allows farmers to shoot dogs that are threatening livestock.

"Whatever their temperament, dogs have a chase instinct that can be triggered by the sight or movement of farm animals. That's why it's so important to keep dogs on leads near livestock and under control at all times."

Farmers can obtain free signs from the NFU by calling 01730 408000 to put up near footpaths, or posters that can be laminated for outdoor use. The signs say: "Even your dog can scare or harm farm animals. Please put it on a lead near livestock."

If a dog worries livestock, the dog owner or the person responsible for the animal at the time is guilty of an offence under the Dogs (Protection of Livestock) Act 1953 and may be sued for compensation by the farmer.

The RSPCA joined forces with the NFU and National Sheep Association to launch an initiative to reduce the number of dog attacks on livestock in 2000.