Mr Stewart said he didn't know which dog attacked first but said the owner of the pig dogs, Rob Coulston, didn't have control of his dogs. He wants Mr Coulston to be banned from walking his dogs on the road, which is a popular area for dog walkers and joggers.
However, Mr Coulston said he had only four dogs with him the day of the fight and that his dogs had never bitten or attacked before.
Mr Coulston said he had been exercising his working dogs on the road for the past 20 years without prior incident.
"I've never had a problem."
On the day in question, he said he had two dogs running in front of his quad bike and two behind when Mr Stewart's two dogs came running towards them down the track.
Thor attacked his dog first, and his dogs reacted in self-defence.
"These two dogs came flying down the track attacking one of my dogs ... It was an unprovoked attack by the male German shepherd."
The owner returned to his bike to get a metal dog lead, which he used to stop the fight.
Two of his dogs, including one valued at $3500, were injured in the incident, Mr Coulston said.
"Nothing I couldn't fix myself."
His dogs were stock and kiwi-proof and not prone to fighting, the meat processor and hunter said.
He said his dogs were hunters, not fighters.
"You can't have a dog that fights - you have to socialise these dogs because they're out with other dogs hunting all the time ... this was a self-defence fight."
Masterton District Council is currently investigating the attack.