Photos provided as evidence to the court showed "the bloodied dead sheep with gruesome injuries to its neck, and with an ear ripped off".
Auckland Council then charged Biggie's owner Allen Pukepuke with owning a dog that attacked stock, and ordered Biggie to be put down.
Pukepuke pleaded guilty in the Waitakere District Court but applied for a discharge without conviction.
Court Judge BR Pidwell rejected his application for a discharge and also ordered Biggie to be put down because there was a "danger that Biggie might next attack a child".
Pukepuke then appealed to the High Court in June this year, hoping to save Biggie's life.
During the case, Justice Pheroze Jagose acknowledged Pukepuke and his wife had "tried hard to manage Biggie along with his brother Duke".
The two dogs had earlier escaped in January 2017 when Duke attacked a stock animal owned by a neighbour. After they escaped again the next month, the Pukepukes rehomed Duke and kept the "more docile" Biggie.
The family also set up a routine to prevent Biggie escaping, whereby they kept him inside at night before letting him into a fully fenced yard in the morning and then taking him to work with them so they could keep an eye on him.
"All family members knew to keep doors and gates locked. Biggie was not permitted into the front part of the property unless supervised," Justice Jagose said in the High Court decision.
But on the day Biggie attacked the sheep, there had been exceptional circumstances, Pukepuke told the court.
This was because outside workers coming to clean the property left the front door and front gate open, allowing Biggie to escape.
While Justice Jagose acknowledged Pukepuke was a responsible dog owner, she said an appeal could only be granted if the attack had been the result of exceptional circumstances, which she found there had not been due to Biggie's previous escapes.
This led Pukepuke to make a final appeal to the Court of Appeal.
But in a decision last Thurday, Justice Christian Whata delayed the hearing until a separate appeal by Pukepuke to have his guilty plea discharged without conviction is heard in the High Court.
He said that case would have a bearing on whether Biggie could be given a stay of execution or not, and so must be heard first.
So what does that mean for Biggie? "He can rest easy for now," Justice Whata said.
He requested Auckland Council delay executing its "destruction" order for Biggie until at least after Pukepuke finished his other court case.
That means that - while it's been a dog of a year so far for Biggie - he can for now continue living with Pukepuke's niece and her seven-year-old son where he was rehomed after last year's attack.
