A big fan and inspiration at the Boston Marathon got a huge honor Wednesday. A portrait of Spencer, a 13-year-old dog known for his iconic “Boston Strong” sign, was unveiled at marathon headquarters in Fairmont Copley Plaza. Spencer’s owners told NBC10 Boston that Spencer is running out of time after being diagnosed with an untreatable form of cancer. “We just…

Source: After Cancer Diagnosis, ‘Boston Strong’ Dog Honored With Portrait, Marathon Medal