[Elevation of the bacteriological content of milk of clinically unaffected lactating bitches of a canine research stock].

In the years 1987-1989 a bacteriological investigation of the milk was made in 44 clinically healthy postparturient bitches. In 30 animals bacteria most commonly isolated were staphylococci. 30.3% (40 samples) of the samples yielded pure cultures and 6.8% (9 samples) anacultures. Small numbers of bacteria were isolated in most of the samples; 67.4% showed moderate bacterial growth (less than or equal to 10(4)/ml sample). In vitro drug sensitivity tests revealed lincomycin, erythromycin and polymyxin B proved to be most efficient. Moreover neomycin, kanamycin and chloramphenicol showed low resistance rates while colistin sulfate and carbenicillin were less effective. A direct influence of lactiferous gland colonization with bacteria on mortality of puppies was not observed. With respect to clinical aspects, the application of antibiotics for sanitation of the lactiferous gland colonization with bacteria in clinically healthy bitches has to be considered carefully. However, for this the estimation of drug sensitivity tests is not satisfactory and should be completed by accurate bacteriological identification.