By Craig Day, The News On 6

BARTLESVILLE, OK -- Police and animal lovers in one Green Country town are shocked and saddened by the loss of a K-9 officer. 

A three-year-old German Shepherd named Cooper who worked for the Bartlesville Police Department had to be euthanized after ingesting anti-freeze. 

That's tough enough. How it may have happened makes it even more tragic.

Bartlesville Police Officer Troy Newell's heart has been heavy. He's mourning the death of his partner, Cooper. They had spent almost every moment together for the past two years.

"He is an officer and he is my partner, and that's no different than if they would have killed my human partner," said Officer Newell.

"We don't know if it was accidental or someone would intentionally do something like that," said Cpt. Jay Hastings, Bartlesville Police Department.

But considering Cooper only left Newell's backyard and home to go to work, and never went anywhere without his handler, they say there's a good chance the poisoning was intentional.

"That's about as low, as low as you can go. That's just horrible," Newell said.

Newell believes someone may have jumped his back fence to target Cooper. His other dogs didn't get sick at all.

"Very lowdown, terrible people," Newell said.

It's a deeply personal loss, and a professional loss for the department.

"This dog went out on traffic stops and searched vehicles for narcotics and things like that, and I believe the dog also had the capability of tracking," said Hastings.

For now, caring for the department's remaining K-9 officer Eddie is making the loss a little easier. The dozens of sympathy cards and letters help too. That support is especially meaningful, as Newell copes with a special bond that has been lost. 

His sadness is now combined with a desire for justice.

"I hope they're ready to go to prison for a very long time," said Newell.

The Bartlesville Police Department expects to get another police dog within the next couple of weeks from Holland to replace Cooper. 

Tips in the case can be called in to the Bartlesville Crime Stoppers at 918-336-CLUE.