Up until October 2017, Dutchess’s worst health issue was an accidental collision with a tree while chasing a squirrel. So the eight-year-old rescue dog’s owner, Lisa Correa, was shocked when a wellness exam at Tufts at Tech Community Veterinary Clinic in Worcester turned up a sign of a serious problem. “They told me they found a lump on her left mammary gland,” said Correa. “And my world pretty much came crashing down.”