In vitro antitreponemal activities of carbadox, virginiamycin, olaquindox, and tylosin as indices of their effectiveness for preventing swine dysentery
Williams, B.J.; Shively, J.E.
Veterinary Medicine-Small Animal Clinician 73(3): 349-351
1978
ISSN/ISBN: 0042-4889 PMID: 418551 Document Number: 136403
Measurement of minimum inhibitory concentrations of the drugs in agar dilution tests was compared with studies in which pigs were allowed access to medicated feeds for 21 to 28 days after challenge with pure cultures, inoculation with caecal-colonic contents and scrapings from pigs infected with pure cultures or exposure for five days to pigs shedding a specific isolate of Treponema hyodysenteriae. Feeds contained carbadox (50 to 55 mg/kg), virginiamycin (50 to 100 mg/kg), tylosin (100 to 110 mg/kg) and olaquindox (50 to 100 mg/kg). The three forms of challenge were approximately equally effective for inducing swine dysentery. The results show that there is a correlation between the in vitro and in vivo activities of these drugs.