A County Armagh sheep farmer said he may abandon his flock after 28 of his lambs were killed in a dog attack in December.
George Carville, of Middletown, said it was a “horrific experience” for him and his teenage son, Frank.
Farm animals worth around £147,000 were seriously injured or killed by dogs last year, insurer NFU Mutual has revealed.
In 2022, the value of attacks on livestock was estimated at £165,000.
Carville said he discovered the attack when he “met a dead lamb at the gate.”
In his field, there were more dead animals, and he told BBC News: “We knew immediately that this was a dog attack.”
He added: “Some of them were pushed into the river and drowned.”
The farmer said his family has used the 50-acre land for more than half a century, and this was the first dog attack since 1983.
“There are a lot of dogs now in Middletown,” he told Good Morning Ulster on Monday.
“It seems like people now maybe don't think – they let a dog out in the evening for a run thinking the dog isn't doing any harm.
“But if you're not responsible for your dog, you won't know where he is, and that's the kind of thing that can happen.”
In all, 13 of George's lambs – some with facial injuries – survived the attack by jumping to the next field.
“We brought them out into the yard, and it was two days before they started eating, and they were in complete shock.”
Pregnancy season
Martin Malone, from NFU Mutual, said: “We urge all dog owners to take responsibility for their pets and keep them on a lead when walking anywhere near livestock.”
The company said it surveyed more than 1,100 dog owners and found that 68% let their dogs off the lead in the countryside last year – compared to 64% in 2022.
“Despite falling costs, the doubling of the number of dog attacks on livestock in Northern Ireland over the past two years is extremely worrying for the country's farmers, particularly as the 2024 lambing season begins and pregnant ewes and newborn lambs are at risk,” Mr Malone said.
“We have heard reports from farmers of the complacency and naivety of some dog owners who regularly allow their pets to wander off-lead into the countryside, seemingly unaware of the carnage a dog can cause – and then are terrified when an attack occurs.”
He said some farmers feared repeated attacks, which could “traumatize” all those dealing with the aftermath of the attack.
“All dogs are capable of chasing, attacking and killing farm animals, regardless of their breed, size or temperament,” Malone added.