Research Update End-year 2 CHF 02519: Prevalence of Bartonella spp. Infection in Dogs with Cardiac and Splenic Hemangiosarcomas Within and Between Geographic Locations

Hemangiosarcoma (HSA) accounts for the majority of canine malignant splenic tumors and occurs in many large dog breeds, including mixed breeds. A less common site of HSA localization is the heart (cardiac HSA). Risk factors for both cardiac and splenic HSA remain unclear, confounding development of preventative strategies. The investigators recently reported a high prevalence of species of the bacterial genus Bartonella in dogs with HSA from North Carolina, suggesting a potential role in the initiation and/or progression of this cancer.

We are on track to accomplish all of our aims for this study. We were able to obtain the initial set of samples on April 26, 2018 so we had a short delay in starting this study. We have now completed all Year I study aims, with the exception of immunohistochemistry and FISH localization of Bartonella organisms within various cell types. We have published a manuscript to the Journal of Clinical Microbiology, representing additional research from our AKC-CHF study #02287, which allowed us to define the Western Blotting (WB) criteria for serodiagnosis of bartonellosis in dogs. That work required additional time and research effort to validate WB testing. We are very excited with the qPCR and ddPCR results obtained from the fresh frozen hemangiosarcoma tissues provided by the NIH-CCOGC.

The results strongly support a role for Bartonella spp. in the etiopathogenesis of hemangiosarcoma in dogs. The regional study should provide additional insight as to the issue of potential causation. All three of the regions have identified, collected and shipped all necessary samples from their region. These samples will be tested by ddPCR, which has required months of validation, over the next six months.

End-Year-2 Research Update Dr. Breitschwerdt for Bartonella infection with hemangiosarcoma.