According to chessbase, 14..Qd8 is by far the most popular continuation in this position (196 games), even though Stockfish 8 seems to prefer 14..Ngf6 (1 game).
I'm struggling to understand the rationale for 14..Qd8, as the queen looks reasonable on a5 for the time being (pinning the pawn on c3, which may allow tactics on d4), while 14..Ngf6 develops a critical piece which allows the black king to castle. Admittedly, after 14..Ngf6, the white attack on g7 can build up quickly with ideas of exchanging knights and then Qg4 and Rh3-g3, but black has defensive resources to deal with it and I fail to see how 14..Qd8 helps in any case.
[FEN ""]
1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 Nd7
8. h5 Bh7 9. Bd3 Bxd3 10. Qxd3 e6 11. Bf4 Qa5+ 12. Bd2 Bb4 13. c3 Be7
14. Bf4 Qd8!? {+0.22 - most popular move}
( 14... Ngf6 { -0.14: Engine likes this better} )