An SPCA investigator broke her back - and spirit - working on the case involving 33 slaughtered dogs, while the culprits walked away with community sentences.

Tony Campbell and Russell Mendoza were yesterday sentenced at the Auckland District Court on four counts of wilful ill-treatment and one of reckless use of a firearm.

The pair went on a shooting spree, killing 23 puppies and 10 adult dogs belonging to Rowan Hargreaves, at a rural property near Wellsford, north of Auckland, in January 2010.

The men each received sentences of six months home detention, 300 hours community work and were ordered to pay the SPCA $4775. They are still allowed to own dogs.

Judge Mary-Beth Sharp encouraged the men to complete their community service at the SPCA, something which staff are apprehensive about.

Vicki Border, a former SPCA investigator who worked on the case, has been following the trial throughout, and was tearful at its conclusion.

Border suffered slipped discs in her spine while exhuming the bodies of the dead dogs. She had her back surgically repaired with titanium screws and never returned to work.

''The dogs suffered, people suffered, it's over but I wouldn't say I'm overly happy with the result.''

The principle investigator who worked alongside her on the case, Sasha Keltie, also quit.

SPCA Auckland executive director Bob Kerridge expressed his disgust at the offending outside court yesterday.

''This was what can only be called a blood thirsty, cruel and inhumane act to animals. I have never seen our inspectors as traumatised as the two who were on this case.''

He said the SPCA is disappointed in the leniency of the sentences.

''The Judge made it clear that the sentencing is there to send a message that animal cruelty is unacceptable, I don't think this sentence sends that.''

Most of the dogs were in cages when they were shot in a 25-minute spree, predominantly at the hands of Campbell.

The shootings were sparked by a dispute between Hargreaves and Mendoza after accusations that one of his dogs had mauled and killed Mendoza's fox terrier.

Hargreaves lived with the dogs - which he described as his "family" - in a disused quarry. He had reluctantly agreed to the adult dogs being put down to keep the peace with his neighbours.

Others had tried to manage the issue of Hargreaves' many dogs, including contacting the Auckland Council which ''did little to nothing'', Judge Sharp said.

Mendoza had ''opened the door'' to the killings, but it was Campbell who was intent on disposing of the dogs, Crown prosecutor Joshua Shaw said.

Judge Sharp recognised that Mendoza was remorseful, having suffered a marriage break-up, break-down of his Wellsford business, and hate mail since news of his offending became public.

Mendoza's involvement was ''spur of the moment'' as a gun was thrust into his hands. Being an animal lover, he regrets it, his lawyer Joe Koppens said.

Campbell didn't express the same sentiments.

''He shows little insight into the situation that he finds himself in,'' Judge Sharp said.

She wanted the sentences to send a public message against animal cruelty.

She took the men's personal circumstances into account, as well as the harm to Hargreaves. She likened his sentiments to a psychological condition predisposing people to ''collect'' pets.

''His victim impact statement makes heavy reading.''

Aggravating factors to what Sharp described as a ''massacre'', included the level and scale of violence, callousness and cruelty, level of premeditation and level of recklessness displayed.

She also ordered that the guns seized during the investigation, including a .22 rifle and semi-automatic 12 gauge shotgun, be destroyed.

- © Fairfax NZ News