Daniel Brighton was found guilty in Campbelltown Local Court in June of two counts of serious cruelty to a dog which had attacked his camel.

He was jailed for three years and four months, with a non-parole period two years and two months.

Mr Brighton was granted bail pending his appeal, which Justice Stephen Rothman allowed in the NSW Supreme Court on Thursday.

He found the magistrate made an error of law and misconstrued a section of the Crimes Act which said a person wasn't guilty of animal cruelty if the conduct occurred during "the extermination of pest animals".

The magistrate did not give the words "pest animal" and "extermination" their ordinary meaning, he said.

According to the undisputed facts found by the magistrate, one of the animals at the mobile petting zoo was a camel, named Alice.

In the early hours of January 16 2016, two dogs entered the farm where Alice was in its pen and attacked the camel, causing it significant injuries to its legs, throat and face.

A witness who was concerned the camel might die told Mr Brighton that "two dogs had jumped up, and they were hanging off her neck, and that they wouldn't let her go, and he had to beat them off with a pole".

Mr Brighton caught one of the dogs, a mature, bull terrier-type breed and tied it to a tree.

"The first charged act of cruelty occurred some 20 minutes after the attack on the camel, when the appellant stabbed the dog at least six times with a pitchfork," the judge said.

"The appellant then started to drive to a vet to obtain pain medication for the camel, leaving the pitchfork in the dog."

The second act occurred when he returned and realised the dog was still alive.

"The appellant suspended the dog from a tree and beat it across the head between 6 and 8 times, with a mallet."

The dog died and was buried on crown land adjacent to the farm.

"This method of seeking to kill the dog, and of eventually killing the dog, was particularly abhorrent and, ultimately, cruel," Justice Rothman said.

But the issue was whether Mr Brighton was "criminally liable" for his conduct.

He found the magistrate erred in holding the dog was not a "pest animal" and that the killing was not an "extermination" as that term is used in the Act.

"The ordinary meaning of the words 'pest animal' includes a mammal that is a nuisance or that is destructive of livestock of other property and the ordinary meaning of 'extermination' includes the act or process of utterly destroying or eliminating a pest animal," the judge said.

"The conduct of the deceased dog rendered it, objectively, a pest animal and the conduct of the appellant was, objectively, open to only one reasonable possibility, namely, that his intention was to rid himself of (or utterly destroy) this pest."

Australian Associated Press