PCR-Based Determination of the Prevalence of Common Venereal Bacterial Pathogens in Breeding Thoroughbreds of South Korea

Taylorella equigenitalis (T. equigenitalis), Klebsiella pneumoniae (K. pneumoniae), and Pseudomonas aeruginosa (P. aeruginosa) are sexually transmittable bacteria known to cause venereal diseases (VD) in horses. T. equigenitalis causes contagious equine metritis (CEM), which is a considerable concern for equine breeding industry. K. pneumoniae and P. aeruginosa may cause endometritis and infertility in susceptible mares. The purpose of this study was to investigate the prevalence of these bacteria among breeding Thoroughbreds in South Korea. External genital swabs were collected from 178 breeding Thoroughbreds, including 11 stallions and 167 mares. The samples were tested using a commercial multiplex real-time PCR kit. T. equigenitalis, P. aeruginosa, and K. pneumoniae were present in 5.6%, 7.3%, and 5.6% of tested Thoroughbreds, respectively. The results highlight the need for regular testing of South Korean Thoroughbreds, particularly those used for breeding, for these bacteria. The regular pre-breeding test for these bacteria will prevent health complications for the horse and financial losses for the owner as a result of VD.