Earlier this week, Jack Richards, an 18-year-old from Essex, England, posted a photo of his pup D'for that went mega viral on Twitter.
When he was 5, Jack's family got D'for as a 7-week-old puppy. "I've basically grown up with him, so we're more or less best mates," he told BuzzFeed.
The family loved their new pup, "but at 6 months we spotted a lump in his skin," Jack told BuzzFeed. "We took him to the vet and after several checkups they told us he had a melanoma, and the worst variety you can have."
"We paid for his operations and treatment to try and fight the cancer, and took D'for to the vet school in Cambridge to see specialists," Jack said. "They then told us through some form of miracle that the treatment had worked!"
"They told us the cancer could come back but the best thing to do is to just go home and enjoy our dog," he said. "Now 13 years later he is still clear of cancer and going strong!"
Thanks to the popularity of his Twitter post, which has more than 26,000 retweets, Jack started a campaign for the National Canine Cancer Foundation to help other dogs just like D'for.