A field study of ovine bacterial meningoencephalitis
Scott, P.R.; Sargison, N.D.; Penny, C.D.; Pirie, R.S.
Veterinary Record 135(7): 154-156
1994
ISSN/ISBN: 0042-4900 PMID: 7985344 Document Number: 425820
Bacterial meningoencephalitis most commonly affected lambs 2 to 4 weeks old (median 3 weeks, range 3 days to 6 months) with clinical signs of episcleral congestion lack of suck reflex, weakness, altered gait and depression extending to stupor, but hyperaesthesia to auditory and tactile stimuli. Opisthotonos was observed during the agonal stages of the disease. The incidence did not exceed 0.5% of lambs at risk on the 8 farms studied. Analysis of lumbosacral cerebrospinal fluid detected a highly significant increase in protein concentration with a neutrophilic pleocytosis, but bacteriological culture yielded organisms in only a few cases. A response was achieved with high doses of dexamethasone and chloramphenicol in only one of 20 cases. Polyarthritis and liver abscesses in a number of lambs provided evidence of a previous bacteraemic or septicaemic episode but no definite source of the central nervous system infection was identified. In common with other infectious bacterial conditions which are prevalent during the early life of sheep, control measures should ensure an adequate transfer of passive antibody, repeated treatments of the navel, and hygienic conditions in the lambing and rearing environments.