A large group of golden retrievers gathered in Boston on Sunday, one day ahead of the 127th running of the Boston Marathon. An estimated 150 dogs met at the Boston Commons to honor Spencer, the official dog of the Boston Marathon, who passed away in February, and Spencer’s niece, Penny, also passed away just a week later.

The dogs wore “Golden Strong” bandanas to honor the late goldens. Massachachusetts Golden Meetups Meetups donated $1,000 in Spencer and Penny’s names to the Morris Animal Foundation for K9 Cancer Research, presenting the donation to Spencer’s owner Rich Powers.

“It’s just so heartwarming to know that he touched, it’s safe to say, millions of lives,” Powers told Runner’s World. “And I think we are accomplishing his legacy of bringing awareness to canine cancer and how it affects family members.”