A man who stabbed a dog to death in a Perth park was described in court as an "animal lover", before being sentenced to a seven-month suspended jail term.

Jayde Paul Rowan, 37, pleaded guilty to killing the golden labrador named Luna at Polyantha Reserve in Apple Blossom Drive, Mirrabooka, on May 17.

At the time of the incident, Luna's 22-year-old owner was at the park with Luna and her other dog, and both were off their leads.

Luna ran over to Rowan, who himself had a small dog, before he crouched down and stabbed the labrador with a pocket knife.

Defence lawyer Michael Tudori told the court Rowan was an "animal lover" who had a number of pets over the years.

He said Rowan's pet dog had died 10 years ago after being attacked by two dogs in a park.

Mr Tudori said when Luna circled Rowan's puppy, he perceived it as a threat but his reaction was not reasonable, and he was "truly regretful and remorseful".

He said he jabbed the labrador using a small pocket knife to try to "deter" it.

Magistrate Steven Heath said he accepted Rowan was a lover of animals and he did not intend to cause serious harm.

Magistrate Heath said given Rowan's history, he had a "heightened sensitivity" when the dogs approached.

"The real error on your part was to have a knife with you ... then thinking the knife was the right way to fend off the labradors," he said.

Magistrate Heath said Rowan's actions were not at the higher end of animal cruelty offences.

'It doesn't give justice to Luna', owner says

Luna's owner Bridgette said she was disappointed with the judge's decision.

"I'm very disappointed, upset and angry in the conviction, because it just doesn't give justice to Luna, but also shows the community ... that it is not only OK to carry a knife and get away with it, but it is also OK to hurt a harmless animal," she said.

"I live on that street, I will never go to that park again, I don't want to even go to my local shops, because I feel scared.

Jayde Paul Rowan leaves court after being handed a suspended sentence for fatally stabbing Luna. ( ABC News: Irena Ceranic )

Bridgette said she did not accept Rowan's apology for killing Luna and did not believe him when he said he was an animal lover.

"I just don't think you can ever apologise for doing something as much as stabbing and killing someone's animal, someone's baby," she said.

"Being an animal owner himself, I just think that is horrible. No animal lover would do that to an animal. That is not right. It is not acceptable."

Rowan was sentenced to a seven-month jail term, suspended for nine months.

The offence of animal cruelty carries a maximum term of five years in jail.

Protesters gather at court

A handful of animal rights protesters gathered outside the court for the man's appearance, holding placards reading "Justice for Luna" and "Harsher Penalties for Animal Cruelty".

Sled, the founder of the Bikers Against Dog Abuse Group who did not provide his surname, said he was there to support Luna's owner.

He said she had been devastated by the loss of her pet.

"It's been a very hard time for her with all the anxiety and stress she's been under, and she didn't feel able to come down to court," he said.

"But she's stoked by all the support she's received."

Dog owner Ella Plazier, who brought her labrador with her, said she knew Luna's owner through the Labradors of Perth Facebook group and had come to court to show her support.

She said the penalties for animal abuse were far too low.

"A slap on the wrist is all they get, but really these days animals are part of our family and it's really very, very cruel that judges don't recognise this," Ms Plazier said.

"They are so much a part of our lives."