"Cops," a Belgian Malinois and the youngest K9 in the city's police department, suffered severe health problems and died in August. He was four years old.
Ethan was part of a program where civilians got to interact with the police station's dogs. When he heard about Cops' passing, he created a GoFundMe page
to raise funds for the purchase of a new police dog.
"Never before has a young person come forward so quickly and definitively to help us like this," said Green Bay's police Chief Andrew Smith. "For this young person to step up without being asked is a reflection of the Green Bay community."
In less than 24 hours, Ethan raised more than $500 and personally delivered the money to Green Bay Police Officer Derek Wicklund.
The department plans to buy a replacement K9 early next year. Wicklund says Ethan may get a chance to pick the new dog's name.
"It will be a great tribute to Ethan and a great reminder of what he has done for us," Wicklund said.
Cops' human partner, Officer Fred Laitinen, thanked Ethan in a heartfelt letter posted online
"My life and career has been changed with the loss of Cops. His toys sit on the floor at home. His kennel sits empty. His bowls are on the counter, and when I look in the rear view mirror in the squad (car), he is no longer looking back at me," he wrote.
"Ethan and his family told me they wanted to start to raise funds to help get a replacement for Cops," Laitinen added. "I am touched and grateful for their support for our Canine Unit, the department, and our community. Ethan is a role model for all of us."
Ethan loves dogs, especially police dogs, and plans to become a K9 handler himself when he grows up.
"I feel good. Feel like I'm helping them," he told CNN affiliate WBAY.
So far, Ethan's campaign has raised more than $1,500 for the Green Bay Police Department's K9 program. His goal is to raise $12,000. For more information and to donate, visit Ethan's GoFundMe page