Federal Departement of Economic Affairs DEA Agroscope Liebefeld-Posieux Research Station ALP Incidence and antibiotic susceptibility of bovine respiratory disease pathogens isolated from the lungs of veal calves with pneumonia in Switzerland M. Rérat, S. Albini, V. Jaquier, D. Hüssy Agroscope Liebefeld-Posieux Research Station ALP Institute of Veterinary Bacteriology, ZOBA, Vetsuisse Faculty, University of Bern Corresponding author: michel.rerat@alp.admin.ch EAAP Annual meeting 9, Barcelona,..9 Introduction EAAP 9, session, abstract nr Bovine respiratory disease = fourth cause of antibiotic use Bovine respiratory disease = economic losses High incidence at arrival of veal calves in fattening units Pro- and metaphylactic treatment with antibiotics Introduction Bovine respiratory disease: EAAP 9, session, abstract nr Climatic conditions temperature toxic gases dust Calf health transport stress vitamin deficiency Infectious agents viruses Infectious agents bacteria Mannheimia haemolytica Pasteurella multocida Mycoplasma bovis
Main objective of the study EAAP 9, session, abstract nr To investigate the incidence and antibiotic susceptibility of the major bovine respiratory bacterial pathogens Evaluation of different pro-/metaphylactic strategies at the entry of veal calves in the fattening unit Materials and methods EAAP 9, session, abstract nr Holstein bull calves from dairy farms group CON no prophylactic treatment n = 9 group DRAX with Draxxin n = group CAS with CAS K n = Materials and methods EAAP 9, session, abstract nr Evaluation of health status with score system for respiratory traits Pneumonia diagnosed by presence of fever, cough, respiratory sounds, dyspnea, reduced feed intake, Transtracheal lavage on day of diagnosis of first episode of pneumonia Treatment of pneumonia with antibiotics (Oxytetracyclin, Florfenicol, or Danofloxacin)
Materials and methods EAAP 9, session, abstract nr Isolation of bacterial pathogens group CON no prophylactic treatment n = n = group DRAX with Draxxin n = group CAS with CAS K n = EAAP 9, session, abstract nr Distribution of isolated pathogens: Group CON DRAX CAS Total Pasteurella multocida Nr of isolates Pasteurella multocida Mannheimia varigena Mannheimia spp. varigena haemolytica Histophilus somni Acinetobacter lwoffi Arcanobacter pyogenes Streptococcus bovis suis Mycoplasma bovis Mycoplasma spp. bovis bovirhinis arginini sp. Contaminated No bacterial growth EAAP 9, session, abstract nr Distribution of sensitive (S), intermediate (I) and resistant (R) Pasteurellaceae isolates: Pathogen Nr of isolates Pasteurella multocida Mannheimia varigena Antibiotic susceptibility S I + R S I + R Penicillin, Ampicillin Gentamicin Chlor-, Oxytetracycline Florfenicol Enro-, Danofloxacin Thrimethoprim/Sulfonamid 9
Distribution of intermediate and resistant Pasteurellaceae isolates in the different groups: Pasteurella multocida (n=) Number of isolates Pen/Amp. Chlor/Oxytetr. Enro/Danofloxacin Trim/Sulf. EAAP 9, session, abstract nr CON (n=) DRAX (n=) CAS (n=) Distribution of intermediate and resistant Pasteurellaceae isolates in the different groups: Mannheimia varigena (n=) Number of isolates 9 Pen/Amp. Chlor/Oxytetr. Enro/Danofloxacin Trim/Sulf. EAAP 9, session, abstract nr CON (n=) DRAX (n=) CAS (n=) Health Status: EAAP 9, session, abstract nr Incidence respiratory impairement, % 9 arrival CON (n=9) DRAX (n=) CAS (n=) Weeks postarrival
EAAP 9, session, abstract nr Growth Performance: Bodyweight, kg 9 CON (n=9) DRAX (n=) CAS (n=) arrival Weeks postarrival Conclusions EAAP 9, session, abstract nr High prevalence of Mannheimia varigena High incidence of intermediate and resistant isolates to tylosin and tilmicosin not appropriate for treatment of Mycoplasma bovis Macrolide antibiotics not appropriate for pneumonia treatment