Epidemiological Studies on Some Infectious Diseases Causing Abortion in Sheep

Abstract

The study was carried out in sheep farms located in North Coast and Desert Road, Egypt for a period of 6 months from April to October, 2020. A total of 100 aborted ewes of local breeds were investigated. Serum samples were obtained to be tested for presence of Brucella and Rift Valley Fever. In addition, stomach contents of aborted foeti, vaginal discharge and placenta of aborted ewes were obtained for the isolation of Salmonella and Listeria. Moreover, a questionnaire form was prepared for each aborted ewe involving; age, breed and type of housing. The recorded results showed that the highest prevalence was due to brucellosis (17%) followed by Salmonellosis (12%) then listeriosis (11%). On contrary, all serum samples were found to be negative for presence of RVF antibodies. Distribution of Salmonella spp. revealed that S. Abortus ovis scored the highest frequency (50%), followed by S. Typhimurium (28.6%) then S. Dublin (14.3%) and S. Agona (7.1%), while distribution of Listeria spp. revealed that L. ivanovii scored the highest frequency (36.8%), followed by L. monocytogenes (31.6%) then L. innocua (21.1%) and L. grayi (10.5%). The effect of age of aborted ewes clarified that the prevalence was increased with increasing age. Also, Rahmani sheep (22.4%) seemed to be more affected by the investigated diseases followed by Baladi sheep and lastly Barki sheep. The effect of type of housing showed that the prevalence of brucellosis, salmonellosis and listeriosis was 23.1, 26.9 and 23.1%, respectively in closed sheep houses while; it was 14.9, 6.8 and 6.8%, respectively in opened sheep houses. Finally, PCR was successfully employed for detection of Brucella in blood samples of aborted ewes.