DOG owners are being warned keep their pets under control as lambing season approaches.

The National Sheep Association (NSA) has joined forces with the RSPCA to campaign for dog owners to act responsibly at a time of year when dog attacks start to rise.

Their campaign was echoed by farm insurer NFU Mutual which said there was a 35 per cent increase in claims costs for dog worrying during 2015.

Every year sheep are killed, maimed and miscarry after being chased and attacked by dogs.

The NSA says it is a serious animal welfare concern and also caused 'a great deal of emotional stress and financial cost' to sheep farmers around the country.

NSA chief executive Phil Stocker said: “A growing number of our members continue to tell us of some horrendous attacks they have suffered to their livestock.

"It is not only the harrowing injuries which out of control dogs have inflicted, but also the losses they have suffered as a result of dogs simply chasing livestock.

“The risk of heavily pregnant ewes aborting is extremely high after suffering the stress of been chased by dogs, not to mention the risk of young lambs becoming separated from their mother at a critical early bonding stage. Lambs will die from starvation or hypothermia when they become separated from their mother and fail to find her again.”

NFU Mutual's rural affairs specialist Tim Price said: “We are all too aware of the heart-break and huge financial loss that dog attacks cause to farmers.

“The majority of dog owners act responsibly and ensure that their dogs are always kept under control and on a lead when near livestock but a small minority either don’t know their responsibilities or simply do not care that their pet can inflict the most terrible injuries on livestock – which can often result in death.”

With half-term approaching and many families with dogs expected to visit the countryside, NFU Mutual urged people to keep control of their dogs at all times to avoid any problems.