Presence of Bacteria in the Reproductive Tract of Healthy Stallions and Its Relation to the Fertility of Mares

Colonization of bacteria in the reproductive tract of both stallions and mares can cause numerous fertility issues. Breeding operations that only utilize natural cover breeding are faced with a difficult challenge to control disease outbreaks of pathogenic bacteria. The current study used Thoroughbred stallions and mares from central Kentucky to (1) investigate the occurrence of potentially pathogenic bacteria on the stallion’s external genitalia based on cultures, (2) determine if there is an impact on pregnancy rates and pregnancy loss when a stallion has a positive culture and continues to breed, and (3) investigate the occurrence of bacteria and type of isolate in the mare’s uterus after breeding by live cover to stallions with or without positive bacterial cultures. [...]