A wool farm in North Somerset says it has lost double the amount of sheep this year after dogs repeatedly spooked their flock during lockdown.
Jeff Naish, who runs Nailsea Wall Farm, said he rescued 46 sheep from a ditch last week which might have drowned if a passing walker had not alerted him.
Mr Naish believes the problem is getting worse this year as more people buy dogs during lockdown.
"Even a dog barking on the other side of a fence can spook a flock," he said.
"I pulled out five dead ewes the other day, all of them were in lamb.
"A lot of people talk about coming to the country and walking, and it's not that they're irresponsible but people don't understand.
"It could be a poodle but sheep see it as a wolf, they will jump in a ditch and that's it."
Izzy Leach, who works on the farm, recently made an online appeal asking dog owners to control their pets.
"When I was pulling this ewe out, two people came past with a dog off the lead," she said.
"I tried to explain but people don't seem to understand, which is why I put the post up."
Ms Leach estimates the farm has lost as many as 50 sheep this year, double the usual number.
She believes walkers are often too embarrassed to alert farmers if their dog is at fault.
"I don't think there's malice in it, but I want to open people's eyes to the problem," she added.
The National Sheep Association advises owners to keep their dogs on a leash around sheep, even if the animal is trusted to return by call.