Dog owners are being urged to keep pets under strict control as an estimated 4,000 sheep are killed or injured in attacks each year.
Each year farmers count the cost of marauding dogs, with thousands of ewes and lambs killed and maimed in attacks.
A dog warden in the Carlow/Kilkenny district, Michael Morrissey, said "responsible dog ownership" should be uppermost in people's minds as the nights draw in.
In the latest attack eight store ewes were killed on a farm in Goresbridge, Co Kilkenny and it follows reports of 11 ewes killed in Co Sligo.
Figures compiled by the IFA estimate up to 4,000 sheep are killed or injured in attacks each year with winter and key spring period proving most deadly.
John Brooks, a Roscommon farmer and sheep chairman of the ICSA, described the stress to farmers in psychological and financial terms of these attacks as "enormous".
"This type of sheep worrying is having a bad effect on sheep farmers and it starts around now as the winter nights draw in," he said.
"Farmers don't want to have to go down to a neighbour to tell him his dog has been worrying sheep or worse again has killed sheep and will have to be put down," he said.
Mr Brooks, whose flock has been attacked by dogs on numerous occasions over the years, pleaded with dog owners to keep their pets under control.
"I don't blame the dog because it's in their DNA to hunt. The problem is with the dog owners who fail to keep their pets under control.
"The dogs will attack both cattle and sheep but the sheep are the most vunerable and the effect of dog worrying on sheep can last a long time," he added.
However, IFA sheep chairman, John Lynskey said the figure of up to 4,000 could be an underestimation of the problem.
"The figures are based on the reported sheep worrying incidents reported to our data base. I would say it is an underestimation by maybe 50pc because many of the sheep kills are caused by dogs belonging to local farmers and the matter is settled between the parties quietly and on the basis that it is not reported," the sheep chairman said.
"I was in Longford last week where one farmer reported dogs killing five of his sheep and another reporting injuries to his flock from marauding dogs. We are coming into the peak winter/spring period when dogs worrying sheep the most," he said.
The farm leaders' remarks were echoed by Mr Morrissey of the Carlow/Kilkenny dog warden service who was called out to deal with last week's attack in Goresbridge in Co Kilkenny.
He said it also fell to him to inform the owner of the dog and to put the dog down.
Mr Morrissey, who has worked with the warden service for a number of years, has a straightforward message for dog owners.
"If your dog attacks sheep your dog gets put down," he says.
He believes dog owners should adopt the same responsible caring attitude to their pets as parents would with their children.
"You wouldn't leave your house and leave a child alone and roaming your property. It's the same with pet dogs. They should be put safely in a kennel or tied up when not under the supervision of its owner.
"It's a question of responsible ownership and that message has to be got across urgently to dog owners," he says.
They are hoping that the planned introduction of microchipping of dogs which comes into effect next March will speedily identify the pets involved in this sheep worrying problem and will raise the awareness of pet owners about their social responsibilities
Agriculture Minister Simon Coveney allocated €100,000 earlier this year to get the scheme up and running for new born pups and it will become mandatory for all dogs next year.
Mr Morrissey says the micro chipping move will help in the detection of predatory dogs, while both Mr Lynskey and Mr Brooks welcome the initiative but say resources on enforcement would have to be provided if the scheme was to be a success.
Mr Lynskey says the message needs to reach owners.