The next day, she was home in Houghton Bay, around 7.5km away, when she says she heard a familiar-sounding bark.
"It was lunchtime ... I was watering the garden before I went to work.
"I heard my dog barking on the beach below."
She said she went down to the beach and saw Ruby, who bounded up to her.
But just as she was reunited with her pet, Ms Cheyne alleges an enraged woman rushed up.
"She accused me of abusing and neglecting the dog ... and she hit me in the face."
Ms Cheyne, 67, described herself as 5ft tall (152cm) and said the larger woman was in her 30s.
Ms Cheyne claimed the woman knocked her down, then grabbed her by the throat, at which point her aikido training kicked in.
"I was trying to move her off me."
A passerby called police. Some men then ran up to the struggling pair, which spooked the younger woman, Ms Cheyne said.
"It was actually my martial arts that saved me. But I did take a few punches to the face.
"It was pretty scary for me."
Despite the alleged attack, she said she held no malice towards the woman, and hoped to meet her during restorative justice.
Life was better when people moved on from vengefulness, she said. "You don't have to carry these things around."
Ms Cheyne believed the woman turned up with Ruby at Houghton Bay because the beach had a designated off-leash dog exercise area.
A Newtown woman aged 37 appeared in the Wellington District Court last month and was charged with stealing a dog, interfering with a vehicle, and injuring with intent.
She will reappear next month.