[Bacterial susceptibility testings of the lower airways of diseased dogs].

OBJECTIVE

In this retrospective study over 5 years the bacterial flora of the deep airways of diseased dogs was sampled using bronchioalveolar lavage and its in-vitro susceptibility to numerous antimicrobial agents was analysed.

MATERIAL AND METHODS

Susceptibility testing of bacterial isolates from 84 dogs performed from 2004 to 2009 were evaluated and compared to data collected in 1999/2000.

RESULTS

The 99 bacterial isolates comprised Pasteurella spp. (27.3%), Bordetella bronchiseptica (20.2%), Staphylococcus spp. (18.2%), Escherichia coli (15.2%), Klebsiella spp. (8.1%), Pseudomonas spp. (7.0%), and Streptococcus spp. (4.0%). Lavage samples of eight dogs revealed simultaneous occurrence of more than one species. The majority of the tested Bordetella bronchiseptica-isolates were susceptible to fluoroquinolones as well as tetracycline, doxycycline and polymyxin B. The number of amoxicillin/clavulanic acid- and chloramphenicol-resistant isolates decreased compared to 1999/2000. The increase of chloramphenicol-susceptible isolates was statistically significant. The tested Staphylococcus-isolates revealed a susceptibility to fluoroquinolones, amoxicillin, cephalexin, doxycycline, and polymyxin B. Compared to the earlier study, a major portion exhibited susceptibility to chloramphenicol and tetracycline. None of the Klebsiella spp. tested in 1999/2000 was resistant to enrofloxacin, whereas only 62.5% of the isolates examined during 2004-2009 were susceptible. A susceptibility of all tested Klebsiella -isolates was detectable with respect to polymyxin B. Regarding E.coli , none of the tested antibiotics revealed an in-vitro activity against all of the tested isolates. The increase of amoxicillin/clavulanic acid-resistant isolates was statistically significant.

CONCLUSION AND CLINICAL RELEVANCE

The study demonstrates the benefits of bronchioalveolar lavage as a diagnostic tool to ensure a responsible utilisation of antibiotics. Most of the tested bacterial isolates were susceptible to fluoroquinolones.