"I yelled at it and it took off. It came back, so I screamed at it again and it took off again.
"It's fight or flight and I fought. I'm lucky, I've been bought up around dogs and I know you have to show no fear," Ms Te Tau said.
She said the two teens were traumatised by the incident. "They were shaking. The dog had tried to climb over their bikes."
Ms Te Tau tried to contain the dog, a red nose pitbull, on her property while she took the boys to hospital.
But when police and a dog ranger arrived later that night, the dog had escaped and two cats were found dead.
One was Ms Te Tau's 17-year old cat Jazz, while another belonged to a neighbour.
Jazz was "ripped apart," she said. "To see him like that was heartbreaking."
The cat had distracted the dog as it was trying to attack the boys, Ms Te Tau said. "He was a brave little moggy, who went out scrapping."
Ms Te Tau said it was important the dog was caught. "We've got to get the message out there.
"That dog was really vicious. I'd hate to think of a little kiddy out there riding their bike and being attacked. It'll have no mercy."
It wasn't the first time the dog had been seen in the area, she said. "I've been told it likes chasing people on bikes."
A dog trap has since been installed in Ms Te Kura's garden by the Masterton District Council's animal control unit, with a piece of dog roll as bait.
Animal control officers visited schools in the area yesterday to warn them of the danger and offer advice on what to do if they saw the dog, said Sue Southey, council manager of environment and planning.