For Buddy, ball was life.

The five-year-old King Shepherd became an internet sensation earlier this year because of his adorable head tilts captured on video and his love of playing ball.

But in early November, Buddy’s owner Mike Lalicich noticed his beloved dog was slowing down.

After several appointments, it was determined that Buddy had cancer and only had four months to live.

“My son said you’ll know when it happens. I said, ‘you’re right.’ I’ll know when he doesn’t want to play ball with me anymore. For buddy, ball was life,” said Lalicich.

RELATED STORY: Niagara dog goes viral

A few days after the diagnosis, Buddy’s owner had to make the difficult decision to put him down after his condition worsened.

“I asked him if he wanted to play ball. I didn’t even get an eye movement from him. It was horrible,” said Lalicich. “Next to my father’s death, it was the greatest loss of my life. It was horrible. I’m flabbergasted by it all and the way it happened.”

The response to Buddy’s death online has been overwhelming and Lalicich says so many people have reached out to say their dogs have also died from cancer.

Niagara Falls city council voted Tuesday to light the falls purple on Thursday to raise awareness about canine cancer and green because of Buddy’s love of tennis balls.