Hawke's Bay police dog, Dirk has had to be put down, despite on-going treatment.
The dog has been having intensive care since handler Senior Constable Mike Warren noticed his crime-fighting companion was struggling to walk in June last year.
It was discovered the four-and-a-half-year-old German Shepherd had a tumour on his spine.
"We had finished a busy week and I knew he was pretty tired... He was just playing, chasing his ball on a day off and his back legs just gave in under him.
"I thought he might have just slipped on something but in the space of 12 hours, he went from being normal to not being able to stand up and walk properly."
In a statement on Tuesday, Warren said the decision to releive Dirk of further suffering was not made lightly.
"Dirk was unable to make any improvement over the last eight months while convalescing, after undergoing serious spinal surgery to remove a tumour from his spine in July 2018.
"Dirk had a number of major setbacks with infections and other related spinal issues. His quality of life was such that he was totally reliant on his carers for support."
He was laid to rest on March 15.
"Dirk is a huge loss to the New Zealand Police and the Hawke's Bay Police Dog Section.
"He was an exceptional police dog and was struck down to soon. He touched many hearts with his awesome nature and loved his cuddles and ear rubs with whoever made a fuss of him.