1College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box; 34, Debre Zeit, Ethiopia.
2Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P. O. Box: 1176, Ethiopia.
3Faculty of Veterinary Medicine, University of Gondar, P. O. Box 196, Gondar, Ethiopia.
Email: [email protected]