Pharmacokinetics of cephalexin following intraVenous and intramuscular administration of 40 mg/Kg were carried out in a cross over study with 15 days interval using 4 female lactating goats. After intravenous adiministration the serum conCentration time curve of cephalexin was best fitTed using two compartements open model, with
Elimination half life t of 0.79 ± 0.12 hours, Volume of distribution at steady state Was 0.32 + 0.04 Ikg ‘ and total body clearence (CL) Was 9.16 ± 1.6ml/h/kg. After intramuscular (i.m) Administration, the drug was rapidly absorbed With an absorption half life (a) of 0.129 ± 0.012 hour, maxium serum concentration © Was 32.9 ± 2.2 ug ml-1 which attained at (T) 0.41 ± 0.012 hours and the drug was eliminated With a half life (t, ) of 0.85 ± 0.062 hour. The Systemic bioavailability (F) after i.m administraTion was 73 ± 5.54 %. The serum protein binding Tendency was 16-22 ± 2.43 %. Following i.m adMinistration of the drug, urine concentrations Were exceeding the minimum inhibitory concenTrations (MIC) for all pathogens responsible for Urinary tract infections in goats for 10 hours. The Drug was detected at low concentrations in milk Of lactating goats. From the aforementioned reSults, cephalexin could be used for treatment of Urinary tract infections in goats at a dose of 40 mg/Kg every 10 hours.