Bluetongue virus serotype 3 (BTV-3) emerged in northwestern Europe in 2023–2024, raising concerns about its potential reproductive impact on rams, similar to previous outbreaks with BTV-8. This study assessed the effect of natural BTV-3 infection on the semen quality of 49 rams in Belgium using two cross-sectional sampling sessions during the 2024 outbreak. Semen and blood were tested for BTV RNA via RT-qPCR, and a composite semen quality score (SQS) was established based on key sperm parameters. On the first sampling date, 75% of rams were viremic, and 19% presented azoospermia. Rams with BTV RNA detectable in both semen and blood had significantly lower SQS and sperm concentrations than those with viral RNA in blood only or none at all. By the second sampling, 53 days later, semen quality had improved markedly, indicating a transient effect of infection. These findings confirm that BTV-3 can severely but temporarily impair ram fertility, particularly when viral replication occurs in the reproductive tract. Given the seasonal overlap between vector activity and breeding programs, these results underscore the importance of integrating reproductive health monitoring into outbreak response strategies.

Characterizing the microbiota is essential to improve the understanding and management of urogenital disorders. Using 16S rDNA sequencing, this study investigated the urogenital microbiota, including urine, vaginal, and prostatic communities, in a litter of 10 healthy beagle puppies from 4 months of age until the completion of the first estrous cycle in females and 18 months in males. A further objective was to compare these microbial profiles with those of their dam. Significant differences were observed between urinary and genital microbiota in both sexes, evolving over time. Notably, in females, puberty and the first estrous cycle were associated with marked changes in the vaginal microbiota, outweighing individual variability. In contrast, urinary microbiota remained stable during female growth. In males, microbiota showed time-dependent and individual-specific progression, with distinct microbial communities identified in the urinary bladder and prostate. Shared genera between the dam and her offspring were observed, but inter-individual variability suggested a limited maternal influence. Further investigation is needed to clarify vertical transmission patterns. In conclusion, the urogenital microbiota of healthy dogs undergoes dynamic and distinct site-specific changes during early life.