Investigation of characteristics and classification for swine vertebral osteomyelitis in South Korea

Vertebral osteomyelitis (VO) is a major cause of condemnation in swine slaughterhouses, leading to economic losses for farmers. This study aimed to investigate the characteristics and classification of VO cases in South Korean slaughterhouses, focusing on their relationship with pyemia and their potential to reduce unnecessary total condemnation.

Our findings confirmed that swine VOs are often associated with tail-biting injuries, particularly in the posterior vertebrae, underscoring tail biting as a prominent risk factor. Trueperella pyogenes were the most prevalent among the bacterial pathogens, while additional less common bacteria were also identified, warranting further research on their potential pathogenic roles. According to the VO classification scheme used in this study, 75% of the 20 VO cases examined were classified as acute VO, whereas the remaining cases were chronic. It was revealed that only 10% (2/20) of the VO cases were in a state of pyemia at the time of slaughter (true pyemia) and these true pyemia cases were found only in the acute VOs.

The VO classification scheme tested in this study demonstrated high sensitivity (100%), indicating its robustness in avoiding false negatives and ensuring food safety. Of the carcasses that could have undergone unnecessary condemnation, 22.2% were excluded. The results indicate that the VO classification scheme is recommended as a measure to reduce unnecessary total condemnation induced by VO.