The Sheriff's office says Winston died of complications from a virus he contracted.
Winston worked with the Sheriff's Department narcotics team.
His current handler, who cannot be identified due to the nature of his work, told KPIC News that Winston was not just his partner. "He was with me 24-7," he said.
His handler has worked with him since October of 2011, and he still remembers the first bust together. He says that he was brand new, and that Winston actually trained him.
"He was already a seasoned drug dog, and I was a brand new handler, so he taught me a lot."
He says that although it wasn't their biggest bust together, only seizing eight pounds of marijuana, the very first one was the most memorable.
"He was a great dog, great nose, and we had a lot of good seizures," he said. "He wasn't just good for us, he was good for the community."
His handler says they are not 100% sure what virus killed the 4-legged officer, but that they saw a couple of different veterinarians. He says Winston's kidneys had shut down, and that there was nothing more they could do for him.
He says Winston will undergo an autopsy so they can find out for sure what it was.
Winston joined the Douglas County Sheriff's Department in 2007.