Metronidazole is bactericidal against susceptible bacteria. Its exact mechanism of action is not completely understood, but it is takenup by anaerobic organisms where it is reduced to an unidentified polar compound. It is believed that this compound is responsible for the drug’s antimicrobial activity by disrupting DNA and nucleic acid synthesis in the bacteria. Metronidazole has activity against most obligate anaerobes including _Bacteroides_ spp _._ (including _B. fragilis_ ), Fusobacterium, Veillonella, _Clostridium_ spp., Peptococcus, and Peptostreptococcus. Actinomyces is frequently resistant to metronidazole. Metronidazole is also trichomonacidal and amebicidal in action and acts as a direct amebicide. Its mechanism of action for its antiprotozoal activity is not understood. It has therapeutic activity against _Entamoeba_ _histolytica_, Trichomonas, Giardia, and _Balantidium_ _coli_ . It acts primarily against the trophozoite forms of Entamoeba rather than encysted forms. Finally, metronidazole has some inhibitive actions on cell-mediated immunity.
Although there are no veterinary-approved metronidazole products, the drug has been used extensively in the treatment of Giardia in both dogs and cats. It is also used clinically in small animals for the treatment of other parasites (Trichomonas and _Balantidium coli_ ) as well as treating both enteric and systemic anaerobic infections. In horses, metronidazole has been used clinically for the treatment of anaerobic infections.
劑量數字暫停提供：VetPro 的劑量改依 DRUGAPI 藥物資料庫對外的內容，DRUGAPI 目前不提供可直接計算的劑量。下方列出 DRUGAPI 的審查結論與劑量審查引用的來源；計算機可手動輸入劑量換算。
肝功能調整：Reduce dose by 50% in severe hepatic impairment
肝功能調整：Reduce dose by 50% in severe hepatic impairment
肝功能調整：Reduce dose by 50% in severe hepatic impairment
確認精確成品、化學型態、濃度、強度基準、供應來源與法域。 確認物種、年齡、繁殖狀態、診斷、感染位置、病原與藥敏資料。 確認肝臟、神經、胃腸與血液狀態，以及過敏與既往不良反應。 逐項核對全部併用藥、監測計畫、停止與救援規則、食用動物及競賽身分。
DRUGAPI 劑量審查引用的獸醫官方標示（各標示只適用於其產品、物種與法域，不可互換）
依出現頻率分組；嚴重副作用獨立列出，臨床上需立即辨識。
renal