A two-way crossover study was conducted in young Bikaneri camels (aged between 12 and 18 months) during the hot summer season to determine the bioavailability, pharmacokinetics and dosage regimens of sulphadimidine (SDM). A dose of 100 mg.kg-1 of SDM was used to study both the intravenous and oral pharmacokinetics of the drug. Analysis of the intravenous data according to a two-compartment pharmacokinetic model revealed that SDM was well distributed in the body (Vd(area):0.862 L.kg-1), had an overall body clearance of 0.035 +/- 0.019 L.h-1.kg-1 and the elimination of half-lives was in the range of 14.2 to 20.6 h. The mean maximum plasma SDM concentration following oral administration was 63.23 +/- 2.33 micrograms.mL-1, which was achieved 24 h after the oral administration. The mean bioavailability of SDM following oral administration was approximately 100%. To achieve and maintain the therapeutically satisfactory plasma sulphadimidine levels of > or = 50 micrograms.mL-1, the optimum dosage regimen for camels following either intravenous or oral administration would be 110 mg.kg-1 as the priming dose and 69 mg.kg-1 as the maintenance dose, to be repeated at 24 h intervals.