Bacteraemia before, during and after tooth extraction in horses in the absence of antimicrobial administration.

BACKGROUND: Transient bacteraemia can occur during tooth extraction in humans, and dogs and can lead to severe infectious sequelae. Several case reports describe distant site infections following equine tooth extraction, but the occurrence of bacteraemia during dental surgery has not been evaluated in the horse. OBJECTIVES: To determine if transient bacteraemia occurs during tooth extraction in horses, describe isolated organisms and compare these with those found in the diseased teeth. STUDY DESIGN: Prospective, observational study. METHODS: Blood was collected aseptically for blood culture before, during and after oral extraction of incisor, canine or cheek teeth from 20 adult horses undergoing dental extraction that had not received antimicrobial agents for at least 4 weeks prior to surgery. Bacteria found in blood cultures were compared with those found in swab samples obtained from the extracted teeth. RESULTS: Eighteen of 20 horses had positive blood cultures at one or more time points. Streptococcus spp., Actinomyces spp., Fusobacterium spp. and Prevotella spp. were most commonly found. Bacterial genera isolated from swab samples of extracted teeth largely corresponded with those identified in blood cultures. MAIN LIMITATIONS: This study was limited by its use of only conventional bacterial culture, the lack of statistical analysis to explore associations between gingiva score and the occurrence of bacteraemia, and the lack of an age-matched control group of horses not undergoing exodontia. CONCLUSIONS: Transient bacteraemia of oral origin commonly occurs during dental extraction in horses. As none of the horses developed complications associated with bacteraemia during the observation period after surgery, the significance of this bacteraemia remains uncertain. The Summary is available in Chinese - see Supporting Information.