Olaquindox is a chemical antimicrobial of the quinoxaline group, closely related to methylacetyl-quinoxaline and carbadox (Linton et al., 1988). The quinoxaline antibiotics are effective against a broad spectrum of gram-negative bacteria (Asplund et al., 1998). Quinoxaline antibiotics are commonly used in swine production for growth promotion and treatment of enteric diseases such as colibacillosis and swine dysentery (Williams and Shively, 1978).
The performance of pigs fed olaquindox was inferior to that of pigs fed acetylspiramycin. This finding is consistent with the findings of Asplund et al. (1998) who reported that olaquindox was less effective than spiramycin in the control of the enteropathogen Yersina enterocolitica.