Two men who shot 33 dogs on a rural property north of Auckland have been found guilty of firearms and animal cruelty charges.

Russell Mendoza and Tony Campbell were found guilty of four charges of animal cruelty and one of reckless use of a firearm by Auckland District Court judge Mary Beth Sharp after a two-week trial, media reported.

They were charged after the killings of the dogs, 21 of which were puppies, at the rural property of Mendoza's neighbour Rowan Hargreaves in Wellsford, north of Auckland, in January 2010.

Prosecutor Josh Shaw said Mendoza claimed his pet fox terrier had been mauled to death by one of Mr Hargreaves' dogs and arrived at Mr Hargreaves' property the next day, where there was a discussion that all Mr Hargreaves' dogs would be killed.

He said Mr Hargreaves signed a document giving them permission to carry out the shootings, but Mendoza went about the killing without considering the dogs' welfare, turning it into "a commando exercise".

Some of the dogs died a slow and painful death after their shooting, he said.

Mendoza and Campbell argued the deaths were not cruel.