Objective There is little available information on the distinction between physiological and pathological bacterial flora in dog semen, or in fractions of the canine ejaculate. In order to improve the diagnostic basis, the present study describes the bacteriological findings in canine semen samples.
Design and procedure The ejaculates were assigned to three groups: Group A, normospermia (n = 30); Group B, teratozoospermia (n = 33); Group C, azoospermia (n = 29).
Results Our data show that irrespective of semen quality, bacterial contamination and stronger bacterial growth is more common in the pre-sperm fraction than in the other two fractions. The number of bacteria and bacterial species did not vary between the three fractions or the three groups of dogs. Bacteria regarded as potentially pathogenic (β-haemolytic Streptococci, Escherichia coli variation haemolytica) could be isolated in every group, with β-haemolytic Streptococci tending to occur more frequently in all ejaculate fractions from dogs with teratozoospermia.
Conclusion These data emphasise that the first fraction is more contaminated with bacteria than the second and third fractions which may be due to bacteria ascending from the urethra. The use of a fractionated collection of canine ejaculates seems to be beneficial to reduce or prevent bacterial contaminations.