The woman's horse was shot twice through the head as an act of vengeance, the court heard.

A 23-year-old man has been jailed for 28 months for shooting and killing a woman's horse in revenge for a relationship break-up.

Christchurch District Court Judge Jane Farish said the shooting by Ryan Thomas Finlinson was an implied threat that if he could shoot the horse, he could do the same to the woman involved.

The judge quoted from the woman's statement to the Probation Service: "She says it was the closest thing to shooting her. She indicated she lost her most prized possession – the thing she loved most in the world."

Judge Farish ordered Finlinson to pay $10,000 to the woman immediately for the loss of the horse, and for the rifle he used to be destroyed by the police.

Defence counsel Kiran Paima said Finlinson had "reacted to a set of circumstances he was unable to process". The shooting of the horse had not been sadistic, or an act of prolonged cruelty. He was remorseful straight afterwards, now had insight into his offending, and had offered payment.

Judge Farish said the aggravating factors were that the horse he destroyed was the woman's beloved pet, and that a firearm had been used in the context of domestic violence.

She said Finlinson admitted charges of assault and destroying the horse, knowing it would cause loss to the woman.

The incident happened after the three-year relationship ended. Finlinson had moved out but was unhappy with the break-up. The woman said he made threats to shoot the horse, or shoot himself.

He went to the woman's house on May 1 and found her there, with another man. He pushed the man into a wall, but did not injure him.

He then went to a paddock nearby and shot the woman's horse twice through the head as an act of vengeance.

The woman was devastated when she found the horse dead in its paddock.

The pre-sentence reports indicated he had little insight into his offending, and was assessed as a high risk of causing serious harm unless there was some intervention.

He was apologetic for the harm to the horse, but the judge said: "I think you have a long way to go to understand the effects of your offending on the woman, and understanding of the harm you have caused to her."

Finlinson returned to court soon after the sentencing for Paima to ask for bail pending an appeal against his sentence, which could not be heard over the holidays. Judge Farish declined.