The general inspector from Tararua District Council drove past the property and saw a dog's body in a sack. He reported the incident to the police and the Dannevirke SPCA.
An SPCA inspector visited the property. There was nobody home. The inspector found a dead, cream-coloured dog in a sack at the back of the property. Beside the sack was a blood-stained metal pipe, 1 metre long and 5cm in diameter, with short cream-coloured hairs stuck in the blood.
The body of the dog and the metal pipe were removed from the property to preserve evidence. The dog was taken to a veterinary clinic for an autopsy.
The veterinarian concluded the dog had received more than one blow to the head and body and was alive during the beating. Death had occurred shortly after the beating due to head injuries, trauma to the chest, and severe shock from bleeding.
The catalogue of injuries suffered by the dog included multiple fractures to the head, a broken left eye socket, a broken upper jaw, severe bruising on the left side of the head and neck, and a broken right hind leg.
The veterinarian found the dog had suffered significant, unnecessary, and unreasonable pain and distress as a result of the beating it had received.
Hawke's Bay Today decided not to print the pictures of the dead dog because they were too graphic.
When questioned by police, Mason admitted hitting the dog with the pipe but claimed he did so only once in retaliation for being bitten and "didn't mean it".
Mason has extensive previous criminal convictions - many of a violent nature - but has not previously been prosecuted by the SPCA for animal welfare matters.
Dannevirke SPCA inspector Brenda Pender said they were happy with the sentence given to Mason.
"We're thrilled with the result from the court, as it sends the right message that this kind of treatment is unacceptable." Central Hawke's Bay SPCA inspector Renee Hickey said more than 18 months of their time and about $4000 was spent by the SPCA to gain a conviction.
However, Mr Lynch said no reparation order was given.
"Reparation was one thing the judge could have imposed for the veterinary fees but, because of the sentence that was imposed being a full-time custodial sentence, that really was enough."
Mr Lynch said although Mason's actions were shocking it was not the worst case of cruelty he had prosecuted.
"I'd probably say this was a middle band. I mean, there are aggregating features of his offending ... the method he used attacking the dog, how long it would have taken to kill the dog and the injuries sustained.
"Other cases are worse because it involved something more sadistic or a larger number of animals."
Royal New Zealand SPCA chief executive Ric Odom said the SPCA was keen to make an example of Mason.
"Due to the defendant's history of violent, anti-social behaviour, we asked for a sentence of imprisonment to hold him properly accountable for this deliberate act of cruelty. "We're very pleased that the judge has agreed with us and handed down a stiff sentence. We can only hope that it acts as a deterrent to this kind of offending."