The study was conducted on three sheep flocks of 424 animals of different ages and sexes and belonged to some farms in Egypt. Clinical observations and examination revealed that 198 animals showed respiratory distress, cough, rise of body temperature and hurried respiration. 120 animals (22 emergency slaughtered and 98 dead) of the total diseased cases formed the material of work. Swabs were aseptically collected from various parts of respiratory system for mycotic and bacteriological studies. Various types of bacteria such as E.Coli, staph aureus, strept. Pyogenes and corynbacterium pyogenes were isolated. Also various types of mycotic species as Aspergillus spp., Mucor spp., Rhizopus spp. and penicillium spp. were isolated. The newly born lambs showed higher prevalence of the disease as compared with older ones. Proper hygienic measurements and the use of suitable medicaments are necessary to control the problem.