Abstract
An investigation was carried out into an outbreak of respiratory disease complex (RDC) in 3641 Menz and Awassi×Menz cross sheep in Central Ethiopia between 1998 and 1999 by clinical, serological, microbiological, post-mortem and histopathological examinations. The monthly incidence of RDC varied from 2.8% to 4.0% and the prevalence was as high as 17%. The case fatality rate was 18%, despite culling of sick sheep. Over 76% of the morbidity occurred in adults, followed by 19% among weaners. Similarly, 62% of the mortality was in adults. However, 27% of the mortality occurred in lambs despite the low morbidity in the group. Significant breed and age differences were seen in the morbidity and mortality rates (p<0.05). Clinical signs, gross and microscopic lesions and serological and bacteriological examinations showed an interplay of several causes of the RDC, including pestes des petits ruminants (PPR) (72.3%, serologically confirmed), lung worms, maedi-visna, bacterial bronchopneumonia (staphylococcal and streptococcal), enzootic pneumonia and some fungal infections. Cold temperatures, which may be as low as –8.5°C at night, are major predisposing factors along with managemental stresses. Vaccination of animals with a homologous PPR vaccine appeared to decrease dramatically the occurrence of the disease, showing that PPR played an important role in the outbreak. Several of the pathogens do not appear to be individually capable of causing the respiratory disease. Appropriate strategies for the prevention of RDC are suggested.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
REFERENCES
ACT, 1990. Twenty years' database for Ethiopia in a geographical information system (GIS) software (Almanac Characterisation Tool). Texas A&M University, Texas, USA
Ayelet, G., 1996. Epidemiological and serological investigation on multi-aetiological ovine respiratory diseases and vaccine trials on the highland of North Sheara (Ethiopia), (DVM thesis, Addis Ababa University, Faculty of Veterinary Medicine, Debre Zeit, Ethiopia), 74 pp
Bekele, T., Woldeab, T., Lahlou-Kassi, A. and Sherington, J., 1992. Factors affecting morbidity and mortality on-farm and on-station in the Ethiopian highland sheep. Acta Tropica, 52, 99-109
Cadoré, J.L., Greenland, T., Cordier, G., Guigen, F. and Mornex, J.F., 1996. Histogenesis of the pulmonary lesions in the course of visna maedi virus-induced pneumonia. Veterinary Research, 27, 419-426
Cutlip, R.C. and Lehmkuhl, H.D., 1986. Eradication of ovine progressive pneumonia from sheep flocks. Journal of the American Veterinary Medical Association, 188, 1026-1027
Di Guardo, G., Condoleo, R. and Autorino, G.L., 1992. Multicentric lymphosarcoma associated with pulmonary adenomatosis (Jaagsiekte), pulmonary lymphoid hyperplasia, and lymphoid interstitial pneumonia in a ewe. Veterinary Pathology, 29, 262-264
Galal, E.S.E., 1983. Sheep germ plasm in Ethiopia. In: Animal Genetic Resources Information, (FAO, Rome), 4-12
Gilmour, J., 1992. Making the most of ovine necropsy. In Practice (UK), 14, 145-150
Gilmour, N.J.L., Martin, W.B., Sharp, J.M., Thompson, D.A., Wells, P.W. and Donachie, W., 1983. Experimental immunisation of lambs with pneumonic pasteurellosis. Research in Veterinary Science, 35, 80-86
Houwers, D.J. and DeBoer, M.J., 1984. Maedi visna control in sheep: half-yearly serological testing with culling of positive ewes and progeny. Veterinary Microbiology, 9, 445-451
ILCA, 1989. ILCA Annual Report 1988, (International Livestock Centre for Africa, Addis Ababa), 46
ILCA, 1995. Annual Report and Programme Highlights, (International Livestock Centre for Africa, Addis Ababa), 23-30
Libeau, G., Dialo, A., Lancelo, R., Colas, F. and Guerre, L., 1995. Development of a competitive ELISA for detecting antibodies to the peste des petits ruminants virus using recombinant N protein. Research in Veterinary Science, 58, 50-55
Lujàn, L., Begara, I., Collie, D.D.S. and Watt, N.J., 1994. Ovine lentivirus (maedi-visna virus) protein expression in sheep alveolar macrophages. Veterinary Pathology, 31, 695-703
Merchant, I.A. and Packer, R.A., 1983. Veterinary Bacteriology and Virology, 7th edn, (CBS Publishers and Distributors, Delhi), 211-250
Mukasa-Mugerwa, E., Lahlou-Kassi, A., Anindo, D., Rege, J.E.O., Tembely, S., Tibbo, M. and Baker, R.L., 2000. Between and within breed variation in lamb survival and risk factors associated with major causes of mortality in indigenous tropical sheep. Small Ruminant Research, 37, 1-12
Njau, B.C., Kasali, O.B., Scholtens, R.G. and Mesfin, D., 1988. Field and laboratory studies of causes of sheep mortality in the Ethiopian highlands. ILCA Bulletin, No. 31, 23-26
Putt, S.N.H., Shaw, A.P.M., Woods, A.J., Tyler, L. and James, A.D., 1988. Veterinary Epidemiology and Economics in Africa: A Manual for Use in the Design and Appraisal of Livestock Health Policy, 2nd edn, (ILCA Manual No. 3; International Livestock Centre for Africa, Addis Ababa), 15-23
Roger, F., 1996. Ovine Pneumopathies Investigations. Preliminary Scientific Report, (National Veterinary Institute, Debre Zeit, Ethiopia), 1-10
SAS, 1994. SAS/STAT User's Guide for Personal Computers, 8th edn, (SAS Institute Inc., Cary, NC)
Thomson, R.G., 1978. General Veterinary Pathology, (W.B. Saunders, Philadelphia), 412-413
Williams-Fulton, N.R., and Simard, C.L., 1989. Evaluation of two management procedures for the control of maedi-visna. Canadian Journal of Veterinary Research, 53, 419-423
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Tibbo, M., Woldemeskel, M. & Gopilo, A. An Outbreak of Respiratory Disease Complex in Sheep in Central Ethiopia. Tropical Animal Health and Production 33, 355–365 (2001). https://doi.org/10.1023/A:1010565905004
Issue Date:
DOI: https://doi.org/10.1023/A:1010565905004