Anticoccidial quinolone; feed additive for livestock. Description of compd: Ball et al., Chem. Ind. (London) 1968, 56. Prepn: BE 698305; M. Davis et al., US 3485845 (1966, 1969 both to May & Baker). Metabolism and residue studies: E. M. Craine et al., J. Agric. Food Chem. 19, 1228 (1971); R. F. Kouba et al., ibid. 1234. Evaluation in experimental ruminant cryptosporidiosis: R. Mancassola et al., Vet. Parasitol. 69, 31 (1997). Mode of action study: E. Del Cacho et al., Int. J. Parasitol. 36, 1515 (2006).