M. U. D. Ahmad, A. Sarwar M. I. Najeeb, M. Nawaz, A. A. Anjum, M. A. Ali, N. Mansur
1 Department of Epidemiology, Faculty of Veterinary Sciences, *Department of Microbiology, Faculty of Veterinary Institute of Molecular Biology and Biotechnology, The University of Lahore.
2 Sciences, University of Veterinary and Animal Sciences, Lahore.