In the last decades, a loss of genetic variability has been observed in the dog population, resulting in a high number of genetic diseases. Increasing the number of reproducers, frozen or chilled storage of spermatozoa and international exchange of semen could be a possible solution. To reach these goals, a canine semen bank was set up by our team. However, a problem of increasing importance is that not all dogs are fit for semen cryopreservation. We hypothesize that the canine seminal microbiome could play an important role in dog fertility and that the gut microbiome could influence this. Firstly, (1) a full description of the seminal microbiome in male dogs of different semen quality will be performed and the presence of specific bacteria will be investigated and linked with genital diseases and semen quality. If a link is found between the gut and seminal microbiome, (2) we will remodel the microbiome by pre/probiotic administration to a more robust state. Finally, we will communicate our findings to the public, since antibiotics are routinely administered by veterinary practitioners in
subfertile dogs without proper diagnosis. Also, antibiotics are often added to semen diluters, but this may contribute to antibiotic resistance in animals and humans. (3) Here, we will investigate several alternatives for antibiotics during semen preservation which will also benefit the One Health Principle.