Encephalitis in aborted bovine fetuses associated with Bovine herpesvirus 1 infection.

Brain tissue from 12 aborted bovine fetuses submitted to the Wisconsin Veterinary Diagnostic Laboratory revealed histologic lesions that consisted of glial nodules and variable degrees of mononuclear inflammation, microhemorrhage, neuronal necrosis, and cerebral cortical cavitation. A diagnosis of Bovine herpesvirus 1 (BHV-1) abortion had been made in all of these cases through multiple testing modalities. Brain tissue from 8 of the 12 fetuses was immunohistochemically stained with a monoclonal antibody specific to BHV-1, and, in 5 fetuses, there was positive intralesional staining of neurons, glial cells, and endothelial cells. This preliminary data suggested that herpesviral infection of brain tissue led to the described neurologic lesions. BHV-1 was then amplified from brain tissue in all 12 of the fetuses and was confirmed by partial sequencing of the thymidine kinase and glycoprotein C genes. To the authors' knowledge, neurologic lesions have not previously been described in BHV-1-infected fetuses, nor has BHV-1 previously been identified in bovine fetal brain tissue. The neurologic histopathology attributed to BHV-1 infection in these cases overlaps with the neurologic lesions produced by Neospora caninum, a common etiologic agent of bovine abortion. Therefore, when bovine fetal neurologic lesions are found, both etiologies should be considered and then distinguished by using additional diagnostic tools.

Investigation of the spread of Brucella canis via the U.S. interstate dog trade.

OBJECTIVES: The aim of this study was to illustrate and help address a growing need for regulatory or molecular tools to track and control the spread of canine brucellosis. Our study objectives were to first characterize Brucella canis outbreaks in Wisconsin kennels in the context of the dog trade in the USA, and then to identify a molecular technique that may be useful for strain differentiation of B. canis isolates. METHODS: Wisconsin Veterinary Diagnostic Laboratory (WVDL) B. canis serology data from 1995 to 2005 were reviewed, three canine brucellosis outbreaks in Wisconsin dog kennels were investigated, and eight B. canis isolates recovered from Wisconsin outbreaks and kennels in Missouri and Arkansas and four isolates received from outside sources were subjected to ribotyping, pulsed-field gel electrophoresis (PFGE), outer membrane protein analysis (OMPA), and cellular fatty acid profiling (CFAP). RESULTS: WVDL has received increasing numbers of B. canis positive samples from Wisconsin kennels, and Wisconsin outbreaks are associated with the interstate dog trade. All of the B. canis isolates we examined were genetically homogenous and as such could not be differentiated by ribotyping, PFGE and OMPA. However, dendrogram analysis of CFAP divided the isolates into two groups, indicating that CFAP methyl ester analysis has discriminatory power. CONCLUSIONS: CFAP methyl ester analysis has promise as a tool for epidemiological tracing of B. canis outbreaks and will be useful in comparison studies as isolation of B. canis continues to expand globally.