Clinicopathologic findings in dogs seroreactive to Bartonella henselae antigens

Objective-To assess the potential clinical relevance of seroreactivity to Bartonella henselae antigens in dogs. Animals-40 dogs seroreactive to B henselae and 45 dogs that did not seroreactivity to B henselae. Procedure-A case-control study was conducted. Clinical and clinicopathologic findings were extracted from medical records of each dog. Results-Statistical differences were not detected between dogs seroreactive or nonseroreactive to B henselae when analyzed on the basis of disease category or results of hematologic, biochemical, urine, or cytologic analysis. However, seroreactivity to B henselae antigens was detected in 2 of 4 dogs with a clinical diagnosis of granulomatous meningoencephalitis, 3 of 4 dogs with immune-mediated hemolytic anemia, 3 of 4 dogs with infective endocarcitis, 2 of 3 dogs with lymphoid neoplasia, and 5 of 10 dogs with polyarthritis. Additionally, seroreactivity to B henselae antigens was detected in 18 of 34 thrombocytopenic dogs and 14 of 27 dogs with neutrophilia. Conclusions and Clinical Relevance-Significant associations were not detected between seroreactivity to B henselae and various diseases. Prospective epidemiologic studies investigating specific diseases, such as meningoencephalitis or polyarthritis, and specific hematologic abnormalities, such as immunemediated hemolytic anemia or thrombocytopenia, should be conducted to further define the potential clinical relevance of antibodies against B henselae in dogs. Impact for Human Medicine-Bartonella organisms are increasingly reported as pathogens that induce chronic infections in humans and dogs. Dogs may serve as natural candidates for future study of the disease in humans.