By CBSBoston.com Staff

ASHLAND (CBS) – Spencer the dog, a fan favorite during the Boston Marathon, is dealing with some serious medical concerns.

Each year Spencer roots for runners along the marathon route in Ashland.

Spencer the Marathon Dog (Photo Via Rick Powers)

Spencer’s owner Rich Powers said the 12-year-old dog had a tumor as well as his spleen removed.

In a Facebook post, Powers said the surgery went well and they are waiting to see if the tumor is cancerous.

CBSBoston.com Staff