Antimicrobial consumption on Austrian dairy farms: an observational study of udder disease treatments based on veterinary medication records oleh Clair L. Firth, Annemarie Käsbohrer, Corina Schleicher, Klemens Fuchs, Christa Egger-Danner, Martin Mayerhofer, Hermann Schobesberger, Josef Köfer, Walter Obritzhauser