A shepherd was a person who herded sheep.
According to one account, which may have been a dream, Jamie McCrimmon stopped travelling with the Second Doctor to become a shepherd in Yorkshire after Zoe Heriot went into a coma. (PROSE: Dream a Little Dream for Me)
When the Slitheen-Blathereen came for dinner with Sarah Jane Smith and her friends, Clyde Langer made shepherd's pie and tomato soup for them. Due to its name, Tree Lorn Acre Slitheen-Blathereen mistakenly assumed that shepherds were a delicacy on Earth. (TV: The Gift)