Mrs. Oleson asks Dr. Baker if he's a "doctor or a veterinarian" after she finds out he's been treating the hidden wolves. Although she calls Dr. Baker a "veterinarian" at other times as a kind of sideways insult, it's established early in the show that Doc Baker is both a human physician and a veterinarian.
The house the Garvey's live in used to the the house the Edwards' lived in
This is Patrick Labyorteaux's first appearance as Andrew Garvey. He will continue the role until the Season 7 episode, "The Lost Ones Part 1." (#21).