Antimicrobial use as an adjunctive treatment in dental-related sinusitis in horses: A systematic review

Dental-related sinusitis is a common condition in horses and often involves polymicrobial infection. Tooth extraction followed by sinus lavage and debridement are the recommended treatment. However, infection may persist or recur due to incomplete removal of infected material or, in rare cases, potential antimicrobial resistance. Although the use of antibiotics may be considered, evidence supporting their indication is scarce. This systematic literature review sets out to examine existing evidence supporting the use of antimicrobial therapy in dental-related sinusitis in horses. Five articles (retrospective studies, prospective studies and case series) were included. Doxycycline, sulphadiazine-trimethoprim, metronidazole and procaine benzylpenicillin combined with neomycin were the most commonly used antimicrobials. Oxytetracycline, gentamicin and cephazolin were used to a lesser extent. Two or more active pharmaceutical substances were often combined. In all studies, antimicrobial therapy was used as an ancillary strategy and criteria for drug selection were not reported. This review highlighted the scarcity of evidence supporting the use of antimicrobials in horses with dental-related sinusitis. In cases with positive clinical outcomes, it was not possible to determine whether clinical improvement was due to antibiotics or other therapeutic interventions. Therefore, the actual contribution of antimicrobials could not be established.