He picked the dog up by its collar, causing it to "cock her head to one side and scream".
Apanui then picked up his dog by its hind legs and threw it to the ground, holding it there as he kicked and punched it.
He then picked the dog up again, raised it above his head and threw it to the ground. Apanui was heard yelling at his dog to get up, but when he realised the dog was dead he walked off.
"In explanation the defendant stated he kicked the dog to discipline it because it was rowdy and nipped him," the summary stated.
Judge Bergseng also convicted and discharged Apanui to one a charge of driving while disqualified last December and one charge of trespassing.
As Apanui left the court he was accosted by Paw Justice co-founder Craig Dunn, who had sat in on his sentencing.
Mr Dunn told Apanui he was "lucky" not to be imprisoned for his offending.
Outside court, Mr Dunn told APNZ that "justice wasn't served".
"That was a five-year jail sentence for wilful ill-treatment of an animal and it ended up being four months' home D."
Apanui should also have been banned for life from owning an animal, not five years, Mr Dunn said.
"For the things he did to that animal, he should be banned for life.
"That animal died for nothing."