sobhan sajadifar department of epidemiology and parasitology, faculty of veterinary medicine and zootechnics, armenian national agrarian university, yerevan, armenia. hadi miranzadeh department of veterinary, university of applied science and technology, institute of science applied higher education of jahad -e- agriculture, isfahan, iran. milad moazeni department of veterinary, university of applied science and technology, institute of science applied higher education of jahad -e- agriculture, isfahan, iran.