[1] Univ London, Royal Vet Coll, Dept Comparat Biomed Sci, London NW1 0TU, England
[2] UCL Sch Pharm, Dept Pharmaceut & Biol Chem, London WC1N 1AX, England
[3] Michael Okpara Univ Agr, Dept Vet Physiol Biochem & Pharmacol, PMB 7267, Umuahia, Abia State, Nigeria