The pharmacokinetics of amoxicillin were studied in five Desert sheep and five Nubian goats after intravenous (i.v.) or intramuscular (i.m.) administration of a single dose of 10 mg/kg body weight. Following i.v. injection, the plasma concentration-versus-time data were best described by a two-compartment open model. The kinetic variables were similar in both species except for the volume of the central compartment (V_c), which was larger in sheep (p<0.05). following="" i.m.="" injection,="" except="" for="" the="" longer="" half-life="" time="" of="" absorption="" in="" goats=""><0.05), there="" were="" no="" significant="" differences="" in="" other="" pharmacokinetic="" parameters="" between="" sheep="" and="" goats.="" the="" route="" of="" amoxicillin="" administration="" had="" no="" significant="" effect="" on="" the="" terminal="" elimination="" half-life="" in="" either="" species.="" the="" bioavailability="" of="" the="" drug="" (f)="" after="" i.m.="" administration="" was="" high="" (="">0.90) in both species. These results indicate that the pharmacokinetics of amoxicillin did not differ between sheep and goats; furthermore, because of the high availability and short half-life of absorption, the i.m. route gives similar results to the i.v. route. Therefore, identical intramuscular and intravenous dose regimens should be applicable to both species.