Famous dog who was the official cheerleader for the Boston Marathon sadly dies aged 13

Spencer, who was the cheerleading dog for the Boston Marathon, has sadly died after a long battle with liver cancer.

Tributes have come pouring in for the pedigree pup, who was adored by all the runners who competed in the prestigious event.

He was 13 years of age.

“We are devastated to share the news of Spencer’s passing,” Spencer’s owner Rich Powers said in an emotional statement.

“We were loaned an incredible gift in 2009 and we had to return the gift last Friday. Spencer passed in our home with the help of our compassionate vet on Friday.”

Spencer made his debut appearance back in 2015, two years after the Boston Marathon bombings.

With 'Boston Strong' flags clenched in his jaw, Spencer stood trackside and supported the runners as they passed him by.

Just three years later, he truly became a local celebrity and household name after he braved the rainy weather and stood out in the cold to encourage the athletes – all while donning a cute yellow cute.

In 2021, thanks to his continued efforts, the Boston Athletic Association named Spencer the official dog of the Boston Marathon.

“Every day that Spencer was here with us he was beating the odds exponentially,” Rich said.

“We have enjoyed sharing our special gift with you all. He has been an inspiration to hundreds of thousands of people. He was an angel on earth. Any who had the good fortune to actually meet him in person can attest that when you touched him he emitted pure energy and light.”

Unfortunately, Spencer required surgery on a tumour back in 2020 and was subsequently diagnosed with spleen cancer a year later.

Sadly, it was terminal.

"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," Rich said in his statement.

“He had some incredible odds to beat, and he beat them. What he’s all about is that you can overcome every single thing you thought you couldn’t.

“His whole existence was to make a difference. And his legacy will hope to continue that.”

Fans flocked to social media to share their condolences as well as reflect on their heartwarming encounters with Spencer.

Leading the outpouring of tributes online was the Boston Athletic Association.

"Spencer, your spirit and determination inspired us all," the organisation said.

"We'll miss you, and are proud to call you a friend and forever the Official Dog of the Boston Marathon."