Joshua Luke Cooper has been sentenced to 18 months prison after stabbing Kosmo the police dog on May 31.

A man who stabbed a police dog in the neck has been sentenced to 18 months prison, but that could have been avoided if a mental health report had been actioned, a judge says.

Christchurch District Court Judge Jane Farish said because of the underfunding of mental health and drug and alcohol assessments, she had no option but to send Joshua Luke Cooper to prison.

Cooper, 29, had mental health issues and was a drug addict, and a report for him was directed by a judge for the sentencing at the Christchurch District Court on Tuesday, but it was not actioned, the judge said.

ALDEN WILLIAMS/STUFF Kosmo takes some time out at the Christchurch Patrol Base while recovering from his injuries.

It would have given her details on his mental insight at the time of the stabbing, she said.

She gave Cooper leave to change an 18 month prison sentence to a home detention sentence if he was eligible for a residential treatment programme.

Cooper was sorry and remorseful for badly wounding the dog Kosmo, but luckily the dog survived, she said.

SUPPLIED Kosmo recovering at a vet clinic after receiving the injuries. (file photo)

On May 31, 2018, Cooper was at his partner's house in Kaiapoi, Canterbury, when he tried to cut his wrists.

His partner called police and a police dog handler and Kosmo went to the address, but Cooper had already left armed with two knives.

The police officer found him and told him to stay still and that he had a dog with him. Cooper took off and the officer released the dog, which latched on to Cooper's arm.

POLICE Constable Craig Moore and his patrol dog Oza, who gave Kosmo the life saving transfusion. (file photo)

Cooper struggled with the dog and stabbed him in the neck, trying to get free.

The police officer said in his victim impact statement if he had been closer when the stabbing happened Cooper could have been shot, the judge said.

Kosmo fell to the ground where he was found about 20 minutes later and flown by helicopter to a Christchurch 24-hour veterinary surgery. He received a blood transfusion from another police dog and a 4 centimetre cut to his throat was treated. The cut narrowly missed his carotid artery.

Cooper's pre-sentence report said he had been seeking out assistance for his addiction issues but had not been offered any help.

Judge Farish sentenced Cooper to prison for 18 months on charges of wounding Kosmo, unlawful possession of a knife in a public place, unlawfully being in a yard, failing to attend a stopping violence programme, unlawfully being in a car, and a breach of the Medicines Act.

She said at the time of the stabbing Cooper was in a very distressed state, and had a chaotic, unstable life with drug addictions.