Grant Amount: $44,106

Dr. Edward B Breitschwerdt, DVM, North Carolina State University

April 1, 2003 - March 31, 2005

Breed(s): -All Dogs

Disease(s): Rickettsial Disease

Abstract

Although Rickettsia rickettsii is a well-characterized cause of acute, severe and sometimes fatal Rocky Mountain spotted fever (RMSF) in dogs and people, the role of other Rickettsia species as a cause of disease in dogs is yet to be established. During the late 1990s, we developed a method using polymerase chain reaction assay, or PCR, to detect the presence of DNA of rickettsial organisms in patient blood samples. This PCR method was developed under the currently accepted assumption that R. rickettsii represents the only clinically relevant Rickettsia species inducing disease in dogs in the United States. Therefore, species differentiation was not deemed necessary. Based upon recent clinical, serologic, and PCR data derived from dogs by our research group, this assumption appears to have been inaccurate. Initial work will focus on determining the gene sequence of isolates previously obtained in tissue culture from clinically ill dogs, sequencing rickettsial DNA amplicons detected by current diagnostic methods, and developing PCR techniques that will differentiate R. rickettsii from other known Rickettsia species. We believe that this approach will reveal previously unrecognized pathogenic rickettsiae. Results will impact diagnostic, therapeutic and preventative strategies affecting the health of dogs in North America and perhaps throughout the world.