The devastating financial impact of dog attacks on livestock has been revealed today.

Rural insurance experts NFU Mutual have put the cost of owners in the north west failing to keep their pets under control as £500,000 in four years.

The figures have emerged just days after details were revealed of a devastating attack near Carlisle in which up to 70 sheep died after being savaged by a dog.

Although there is research which suggests more dog owners are putting their pets on leads when livestock is nearby, the insurer says it is increasingly concerned that many attacks are being caused by dogs which have been let out in gardens, escaping and attacking sheep in neighbouring fields.

And it has issued a call for owners to ensure their animals are not just on leads but properly secured when at their homes as well.

Rebecca Davidson, a rural insurance specialist for NFU Mutual, said: “Dog attacks are still at a very high level.

“We are receiving increasing reports of dogs escaping from homes and attacking sheep, either because their owners do not know or do not care that their dogs are roaming wild and causing havoc.

“Thousands of sheep are being killed and horribly mutilated by dogs and we will be redoubling our efforts to raise awareness of the issue, and helping police to bring owners of dogs which attack livestock to justice.

“We are sadly all too aware of the heartbreak and distress that dog attacks cause.”

The knock-on impact of livestock worrying on farm breeding programmes through the losses can take years to overcome, the insurer says.

As well as attacks physically killing animals, the stress can cause miscarriages among sheep which have been chased by out-of-control dogs.

The peak time for worrying incidents is between January and April, which coincides with the lambing season.

In the wake of the incident near Carlisle, PC Helen Branthwaite, Cumbria’s wildlife crime coordinator, said: “Sheep Worrying is a criminal offence. As well as the injury and suffering inflicted upon the animals, it can cause huge financial cost to the farmer and ultimately lead to prosecution of the owner or person in control of the dog at the time.”

The Lake District National Park Authority has also issued a plea for dog owners to act responsibly in the countryside, placing signs urging extra caution in areas lambing is taking place.