Experimental timeline. Trimethoprim sulfadiazine (TMS) administration for 5 consecutive days (Days 0 to 4). Transplants were performed by nasogastric tube for 3 consecutive days (Days 7, 8, 9). Group 1 (3 horses) received 3.2 L of concentrated FMT (cFMT) q12h for 3 d. Group 2 (3 horses) received 3.2 L fresh unconcentrated fFMT (fFMT) q24h for 3 d. Group 3 (3 horses), the vehicle recipients (VEH) received 3.2 L 10% glycerol in 0.9% saline solution q24h for 3 d. Fecal samples were collected on Days 0, 4, 7, 8, 9, 11, and 21.