Mr Kennedy said it had been a rare occasion that both he and his wife had been at home during the week day.
He had heard Shelley's poodle Paloma "barking in a different way than it normally barks" so he looked out the window and saw the two horses running around the paddock.
He got in his ute and raced down the driveway to try to fend off what he thought was an American Staffordshire terrier and another dog of unknown breed, who were chasing the horses.
"The pony comes across and the dog latched on to its leg and I had enough brains to grab a great big long iron bar," Mr Kennedy said.
"The pony ended up on the ground being dragged down by the dog that wouldn't let go and I just upped the pinch bar up and went boof, straight in the middle of its back.
"And then it let go and the pony escaped out through the gate."
Mr Kennedy said he had been following the dogs in his ute as they ran home, when he chanced upon two police officers, who had been at Masterton Primary School.
"So I waved them down and said I need some help here."
He said the police called animal control and the dogs were picked up and put in the pound.
"The street would never have heard such terrible language and with me driving up and down the street like a maniac," he said.
"If we had been 30 seconds later getting here that horse there would not be alive, that's a fact."
He said the dog would have gone for him had he not "been an angry person" with the pinch bar in his hands.
Mr Kennedy said he could sympathise with Mrs Parris because last year rogue dogs had killed one of his sheep and an alpaca on his property.
Mrs Parris, who has only had the two miniature horses for three months, said she had raced back over the Rimutaka Hill as soon as she found out about the attack.
When she got home the vet had already patched up the horses.
Mrs Parris's younger horse, Poppy, was covered in wounds.
"She's been stitched up in about eight to 10 spots."
Mother Rosie had bites to her front leg.
Both horses were "really nice natured" but now Rosie was standoffish and distressed.
Masterton District Council manager of planning and regulatory services Sue Southey said dog attacks were "extremely distressing" for all parties concerned.
"Both dogs are in our pound and we are looking to meet with the owner as soon as possible to confirm the fate of the dogs."
