Alone, sulfonamides are bacteriostatic agents and trimethoprim is bactericidal, but when used in combination, the potentiated sulfas are bactericidal. Potentiated sulfas sequentially inhibit enzymes in the folic acid pathway, inhibiting bacterial thymidine synthesis. The sulfonamide blocks the conversion of para-aminobenzoic acid (PABA) to dihydrofolic acid (DFA), and trimethoprim blocks the 848 sulfadiazine/trimethoprim; sulfamethoxazole/trimethoprim
Although only approved for use in dogs and horses, trimethoprim/ sulfadiazine etc. is used in many species to treat infections caused by susceptible organisms. See Dosage section for more information.
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。
執行前須確認精確品項、兩成分基準與比例、劑型、濃度、物種、感染部位、病原與藥敏、途徑、個案腎肝與泌尿風險、監測、停止與再評估條件，以及法域與標示版本。 食用動物另須核對精確品項的適用族群、產蛋限制與停藥期。
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。