๐พ Dogs in a hand-held carrier travel free on all NS trains. Larger dogs need a Dagkaart Hond (Day Pass for Dogs, โฌ3.30, unlimited NS travel that day) and must be on a leash with a muzzle available in case of complaint. Intercity to Amsterdam Centraal 2h05, to Utrecht Centraal 1h45, to Schiphol 2h15, to Zwolle 1h00, to Leeuwarden 50 min (Arriva regional).
๐ก Buy the Dagkaart Hond at any yellow NS machine in the art-nouveau concourse of Groningen Centraal before boarding; one ticket covers all NS travel that day, including the side trips to Zwolle, Leeuwarden and Amsterdam.