Tony Campbell asked his neighbour if he had a couple of favourite dogs but was told "no, just shoot them all", a court has heard.
Campbell is giving evidence in his own defence at the Auckland District Court. The Crown says he and Russell Mendoza went on a "commando exercise" north of Auckland in January 2010, causing pain and distress when they shot 33 of Rowan Hargreaves' dogs.
The pair have denied four charges of wilfully ill-treating an animal.
The charges carry a maximum three years' imprisonment.
Campbell told the court today that Mr Hargreaves' friend invited him to get rid of dogs at Mr Hargreaves' property - an old quarry near Wellsford.
The South Islander who calls himself Tussock said he was experienced in pest control and was experienced with guns.
Campbell said he "prepared his tools" and packed a number of firearms including shotguns, a .22 rifle and a 44 magnum.
He said he took Mendoza along as a witness and they were greeted by Mr Hargreaves who shook his hand.
"I asked him: 'You know, you must have a couple of favourites'. He said: 'No, just shoot them all'."
Campbell said he offered to take away the corpses but Mr Hargreaves said the dogs were born on his property and he wanted them to be buried there.
"I actually knew how he felt," Mr Campbell said.
He said Hargreaves later told him: "They all have got to go, they've gotten out of hand."
Campbell said he turned to leave three times but Mr Hargreaves asked him to help him get rid of the animals.
"He put his hand on my shoulder and said please don't go, it's gotten out of hand. My friends have told me it has got to be done."
Campbell said he was not happy having Mr Hargreaves there but told him "I will help you".
He said he got Mr Hargreaves to sign a piece of paper which said he would have no legal "come-back".
The Crown alleges Campbell and Mendoza shot 33 dogs, including 21 puppies.
The court has previously heard from Mr Hargreaves who said he signed the paper under duress.
Mr Hargreaves told the court last week that he did not expect any of the puppies to be shot and certainly not all of his dogs.
"They were my family and friends. I couldn't stand there and watch them being put down."
The court has heard how Mendoza and Campbell went to Mr Hargreaves' home after Mendoza's fox terrier had been mauled by one of Hargreaves' dogs.
Campbell's lawyer, Barry Hart, asked his client if he was angry and how he felt about shooting the animals.
"I felt sad. I felt sad that the way those dogs have been kept. I felt sorry for the way those dogs had been kept."
In his opening address, Mr Hart said Campbell was asked to destroy the dogs and did it in a calm almost dispassionate manner.
"He carefully identified the target and ensured no one was in the area."
Mr Hart asked Judge Mary Beth Sharp not to find his client guilty, on the basis that the charges had not been proven.
The trial is due to end this week.