Ian Potter, who farms at Lambrigg Park Farm, between Kendal and Sedbergh, Cumbria, had 11 sheep killed during a couple of incidents between November 2015 and this January.
With more than 60 sheep attacked in total, Mr Potter said the two dogs belonged to a neighbour and he was keen for them to be put down because of the destruction they caused.
But Mr Potter, who saw a mixture of Swaledales and Mule/Texel hoggs killed in the attack, said Cumbria police had not followed up the case.
He said: “The police did not seem to be interested or take it seriously. I saw the two Alsations, knew they belonged to a neighbour and wanted them putting down, but the police said me and my workman were biased witnesses and would not take the case any further.
“It is not just the killing which is the problem, but the aftershock for many of those animals which have been attacked but survived.”
Mr Potter had been encouraged to speak out after seeing the March 11 edition of Farmers Guardian, in which the horrific case of 116 sheep killed by dogs in Sussex was covered.
With no footpaths across his land, Mr Potter said dog owners leaving their pets unsupervised in gardens or yards could have serious repercussions if they escaped.
He said: “The neighbour was leaving the dogs outside at night or when he was at work and this allowed them to do what they did. Hopefully, he has learned his lesson and this will not happen again.
“People do not believe their dogs can do the damage they do. These dogs could have attacked my workmen, not just the sheep, and they are a real threat.”
A Cumbria Police spokesman said officers were investigating the attack.
He said: "Cumbria Police can confirm they have been investigating and are continuing to make further enquiries relating to the reported incidents but currently there is insufficient evidence to prosecute any persons."
With sponsorship from The Original Muck Boot Company, Farmers Guardian has been working alongside the British Veterinary Association and the National Sheep Association to raise awareness of dog attacks via its Take the Lead campaign.
Sean Wensley, president of the British Veterinary Association, said: “Vets see first-hand the terrible damage done when dogs are not kept under control around livestock, especially during lambing season.
"Chasing and attacks can lead to serious injuries, fatalities and spontaneous abortion for sheep and other livestock due to stress.
"We don’t want to discourage people from walking their dogs in the countryside, as it has health benefits for both owner and pet, however making sure your dog is on a lead near livestock prevents avoidable attacks and keeps your dog safe too."
We have thousands of livestock worrying signs which you can nail to gateposts or fenceposts near footpaths to highlight the problem to walkers.
If you would like some of these signs, please send a stamped, self-addressed A4 envelope to
FG Take the Lead, Farmers Guardian,
Unit 4, Fulwood Business Park,
You will need at least three First Class or Second Class stamps on to cover postage costs. We will be able send up to 25 signs.