A woman who was forced to give up all her animals and banned from owning any more for 10 years is challenging the penalties.
Anne Power was found guilty of recklessly ill-treating a horse and causing its death, after a two-day trial at North Shore District Court in March.
At sentencing three months later, Judge Nevin Dawson accepted the SPCA's suggestion for Power to forfeit her many animals and he imposed the decade-long ban.
In the High Court at Auckland this afternoon her lawyer Dan Gardiner argued against both her conviction and sentence, calling it a "miscarriage of justice".
He questioned the recklessness of the alleged act and whether the alleged recklessness actually led to the death of the 32-year-old horse.
Mr Gardiner said it was accepted by the judge that Power loved animals and had spent $30,000 on veterinary bills over the past five years.
"I'd submit that it defies common sense that a person prepared to spend that amount of money on animals could be reckless or uncaring or deliberately blind in relation to the care of this horse," he said.
Three animal experts were called by the prosecution at trial and Mr Gardiner said none of them definitively concluded the horse died of starvation, but that was Judge Dawson's eventual finding.
He said tests undertaken after the horse died showed it suffered from "a number of latent conditions" that may not have been spotted by a lay person, thus making recklessness unlikely.
The lawyer submitted the judge did not assess the evidence correctly, disregarding issues that did not fit the prosecution's case.
"He goes off on a voyage of his own," Mr Gardiner said.
The forfeiture of all her animals was "totally disproportionate to the offence" he said, particularly because the judge did not ascertain how many animals she owned.
Shortly after sentencing, the SPCA seized 56 cattle and sold them at auction.
Mr Gardiner said Power believed they had been grossly undervalued, leaving her out of pocket by up to $30,000.
Counsel for the SPCA John Billington, QC, will make submissions this afternoon and it is likely Justice Pamela Andrews will reserve her decision.