Hunter, who had been diagnosed with an aggressive form of liver cancer, received a final salute from fellow officers.
A heartbreaking image shows a tearful Connecticut police officer saying farewell to his beloved K-9 partner.
Officer Michael D'Aresta of the Middletown Police Department made the tough decision to put Hunter down after he was recently diagnosed with an aggressive form of liver cancer.
Read: K-9 Officer Alerts Border Control To Pair Being Smuggled Into U.S. in Trunk
Photographs shared to the department's Facebook page Friday show D'Aresta with his face in the German shepherd's fur as he carries him past fellow, saluting officers to a veterinary clinic.
"Hunter and Officer D'Aresta have been such a huge part of our department the past ten years," Sergeant Doug Clark, a K-9 supervisor with the department, wrote on the post. "Such a dedicated K-9 team. It will never be the same."
The photo has been shared more than 1,500 times on Facebook.
Speaking to InsideEdition.com, Angela D'Aresta, who attended the ceremony to say goodbye to Hunter, recalled the dog's kind, sociable nature. She said he loved going to work and playing with the family's children, as well as his favorite ball.
Read: Dog Overjoyed to See Owner Weeks After They Were Struck by a Drunk Driver
"He had a great, strong relationship with Mike," she said. "They were best friends besides being working partners."
The K-9's illness "came on him quickly," she said.
"When Mike told me he wasn't doing well and had to put him down, I was so upset and couldn't believe it," she said. "We are all very sad. He was a big part of our lives, especially Mike's... He will be truly missed."
Hunter started working for the city in 2007 and the department has publicly praised him for his work over the years.
In 2015, he found an elderly woman with dementia in a stream after she became disorientated. Last year, he tracked down an unconscious man in a hard-to-reach wooded area, and as recently as July, he helped find key evidence in a drug bust.
Two weeks later, he helped his fellow officers apprehend an injured man who appeared to be intoxicated.
"Great team effort to all the Officers on scene and especially K9 Hunter who prevented the Officers involved from being further attacked and / or injured," the department wrote at the time.
Hunter was put to sleep at the Pieper-Olson Veterinary Hospital in Middletown on Friday.
"Rest in Peace Hunter," Sgt. Clark wrote on one of the photographs. "You've done well."
Watch: Terminally Ill Rescue Dog Sworn in as K-9 Officer as Part of Bucket List
