Book of Abstracts of the 60th Annual Meeting of the European Association for Animal Production
Book of abstracts No. 15 (2009) Barcelona, Spain 24-27 August 2009
ningen Academic b l i s h e r s
EAAP – 60th Annual Meeting, Barcelona 2009 339
Session 35 Theatre 5
Incidence and antibiotic susceptibility of bovine respiratory disease pathogens isolated from the lungs of veal calves with pneumonia in Switzerland
Rérat, M.1, Albini, S.2, Jaquier, V.2 and Hüssy, D.2, 1Agroscope Liebefeld-Posieux Research Station ALP, Tioleyre 4, P.O. Box 64, 1725 Posieux, Switzerland, 2Institute of Veterinary Bacteriology, ZOBA, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, P.O. Box 8466, 3001 Bern, Switzerland; michel.rerat@
alp.admin.ch
The present study was carried out to investigate the incidence and antibiotic susceptibility of the major bovine respiratory bacterial pathogens in veal calves with pneumonia. At the entry in the fattening unit the calves were prophylactically treated either by a single administration of tulathromycin (group A, n=20) or by a peroral administration of chlortetracycline, sulfamidine, and tylosine (group B, n=20) or not prophylactically treated (group C, n=19). All calves had the same housing and feeding conditions. Mucus samples from the lower respiratory tract were obtained by transtracheal lavage prior to first therapeutic treatment on the day of diagnosis of pneumonia. Samples were cultured to identify bacterial pathogens.
During the study, 15 calves in group A, 12 in group B and 18 in group C suffered from at least one pneumonia episode. From the 91 isolated pathogens, the most prevalent were Pasteurella multocida (22% of isolated pathogens), Mycoplasma bovis (18%), and Mannheimia varigena (15%). Pasteurellaceae isolates were tested for their antibiotic susceptibility. All Pasteurella multocida (n=20), Mannheimia varigena (n=13), and Mannheimia haemolytica (n=4) isolates were susceptible to gentamicin and florfenicol. Resistances were found to trimethoprim/sulfonamid (35%, 8% and 0% resistant isolates, respectively), to penicillin (10%, 8% and 50%) and to tetracycline (10%, 15% and 50%). In conclusion, the majority of the bovine pathogens isolated from the lower respiratoy tract of calves with pneumonia in this study belonged to the commensal bacterial flora of the upper respiratory tract. Trimethoprim/sulfonamid, penicillin, and tetracycline should not be used as first choice for the therapy of pneumonia in veal calves in the area under study.
