1. Department of Pathobiology, School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, Neudamm Campus, Private Bag 13301, Windhoek, Namibia
2. Central Veterinary Laboratory, 24 Goethe Street Private Bag 18137, Windhoek, Namibia
3. Animal Production and Health Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Wagramer Strasse 5, PO Box 100, A-1400 Vienna, Austri