A walker feared his mother would die when she was trampled by cows while walking in the Lake District.
Mark Livesy was with his 82-year-old mother and friends when they were attacked by cows on land at Cartmel Fell in Cumbria earlier this month.
She suffered a broken arm and her 15-year-old dog Harvey was killed during the 30-minute attack.
Mr Livesy has called for signs to be made mandatory in fields containing nursing cattle.
His call comes after the death of a teacher in Richmond on Monday.
'Lucky to be alive'
Mr Livesy told BBC Cumbria the group saw the herd drinking from a stream which the walkers had to cross.
He said the dog was on a lead and "didn't do anything to antagonise the cows but they just turned and attacked him".
"They appeared to be fine and calm," he said. "It literally became a frenzy. The poor dog went to the ground and they just started to trample him.
"My mother was knocked to the ground and they started trampling on her."
He said he "honestly thought" she was going to be killed as he and a friend fended the cows off with their walking sticks.
His mother, from Kirkby Lonsdale, suffered a broken arm and bruising, and is still recovering.
"I'm definitely lucky to be alive and certainly my mother is," Mr Livesy added.
He said he supported farmers but there should be a law ordering them to put up a sign warning of "nursing cattle or a bull" so walkers know before they use a path.
The Health and Safety Executive advises farmers to put up signs in such circumstances.
A spokesperson for the National Farmers' Union said: "We are currently seeking an amendment to the Highways Act 1980 that, if made, would allow farmers to divert public rights of way where livestock are present to help keep everyone safe in the countryside."