Prevalence and antibiotic resistance of bacterial pathogens isolated from dogs

This study is to give a survey of the infectious bacterial agents isolated from dogs and of their antimicrobial susceptibility. The results of routine bacteriologic examinations of a broad variety of clinical samples from dog s during the years 1991 through 1994 at the Institute of Microbiology and I nfectious Diseases, Hannover Veterinary School, Germany, were compiled and evaluated with regard to other studies published. Among the 4692 samples included in this study there were specimens from the skin, the conjunctiva, the urogenital tract, the respiratory tract, from t he bones and joints, the intestinal tract and organs from dead puppies. Staphylococcus (Staph.) intermedius was among the most frequently isolated bacteria. It predominated in samples from the skin (87,4 % of the skin spec imens containing bacteria), the mucous membranes of the body orifices (for example 31,9 % of the vaginal swab, 45,5 % of the conjunctival swabs) as we ll as in samples from bones and joints (68,6 % and 24,3 % respectively). Be ta-hemolytic Streptococci were cultivated from similar sites as Staph. inte rmedius though less frequently (16,4 % of the skin samples, 29,1 % of the v aginal samples, 9,0 % of the concunctival swabs, 4,0 % of the bones and 2,8 % of the joints). The bacterium most common in urogenital samples was Esch erichia (E.) coli. It was grown from 55,2 % of the urine samples, from 72,8 % ob the uterine swabs and from 56,5 % of the samples obtained from the pr ostata. Samples from the respiratory tract often contained Pasteurella mult ocida or other Pasteurella spp. (for example 35,5 % of the tracheal swabs) but also E. coli and alpha- or gamma-hemolytic Streptococci, the significan ce of the latter depending on the circumstances of the particular case of a diseased dog. The evaluation of the 3562 results of sensitivity testings showed that in i nfections with Staphylococci, Enterococci, Pseudomonas spp., E. coli and Pr oteus spp. one has increasingly to be aware of resistances of these bacteri a against the routinely used antibiotics. Most staphylococcal strains were resistant to beta-lactam antibiotics with exception of oxacillin (resistanc e rate 3,2 %), cephalexin (resistance rate 6,0%) and amoxicillin-clavulanic acid (resistance rate 2,0%). Many isolates of E. coli proved to be resista nt to broad spectrum antibiotics such as chloramphenicol (34,6 %), oxytetra cycline (46,5 %) and trimethoprim-sulfamethoxazole (28,2 %). Pseudomonas sp p., Enterococci and Proteus spp. were susceptible to hardly any of the anti biotics tested.