Beloved Boston Marathon Dog Dead After 'Severe Medical Challenges': 'We Are Devastated'

Spencer, a beloved golden retriever known for cheering on runners in the Boston Marathon, has died. He was 13.

He died on Friday after overcoming multiple bouts of cancer, according to an Instagram post from his owner, Rich Powers.

"We are devastated to share the news of Spencer's passing," Powers said. "We were loaned [an] incredible gift in 2009 and we had to return the gift last Friday."

Spencer first went viral in 2018 while holding "Boston Strong" flags in his mouth during the rain-soaked race that year at his usual spot on the route near Ashland State Park for nine years, according to WCVB-TV in Boston.

RELATED: Golden Retriever Cheerleader Returns to Boston Marathon After 'Miraculously' Surviving Tumor

The beloved pooch took a two-and-a-half-year break during the pandemic and while he battled cancer, returning to rally runners as they passed through in 2021 despite his health scares.

"Spencer has overcome some severe medical challenges over the past several years. We thought we would be lucky to have him for an extra month," Powers' Instagram post read. "Spencer was not ready to give up and with the love and positive energy sent to him by hundreds of thousands of fans, He beat the odds and gave us 28 months."

Prior to the marathon in 2022, the Boston Athletic Association named Spencer the official dog of the 126th Boston Marathon. He was named the official dog during a ceremony at the Fairmont Copley Plaza in Boston near the finish line.

RELATED VIDEO: 12-Year-Old Golden Retriever Returns to Boston Marathon After 'Miraculously' Surviving Tumor

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Spencer survived having a 3.5-pound tumor removal to make it back to the Boston Marathon, WCVB-TV reported.

"We at the B.A.A. are saddened to learn of the passing of one of our dearest and most loyal Boston Marathon supporters, Spencer," the Boston Athletic Association wrote in a statement to the news outlet. "Spencer annually encouraged participants in Ashland, embodying the unwavering spirit of Boston's athletes as he showed up year after year regardless of the weather conditions. We were honored to have recognized Spencer as the Official Dog of the Boston Marathon in 2022, and extend our condolences to the Powers family, sister Penny, and his many friends and admirers around the world."

RELATED: Ralphie the 'Demon' Dog Returned to Shelter After Just 2 Weeks in New Home

Spencer spent his last day "eating his sweet potato treats, drinking water and enjoying visitors," according to Instagram.

"Spencer being true Spence gave us his last gift. He did not want us to wonder forever if we had made the right decision," Powers wrote.

Minutes before the vet was scheduled to arrive, Spencer began to shut down.

"A few minutes later With the help of our local vet, Spencer passed at home while we held him, thanked him and told him we loved him," Powers said.