Feline cytauxzoonosis is an emerging infectious disease that can be fatal to domestic cats, and early diagnosis and treatment is critical to recovery. It is caused by Cytauxzoon felis, a protozoan parasite that has a life cycle involving bobcats as definitive hosts and the lone star tick (Amblyomma americanum) as its primary natural vector. More recent research indicates that domestic cats may also serve as carriers. However, diagnostic testing is not routinely available for this parasite, and little is known about its prevalence in wild or domestic cat populations, impact, or transmission dynamics. This parasite is present in more than 16 states in the mid-western, southeastern and mid-Atlantic United States, but so far has not been confirmed further north than Pennsylvania where it was detected in 2008. In New York, bobcats have increased in abundance in recent years, and lone star ticks are moving north, recently becoming the dominant tick species on Long Island. No systematic, targeted studies have ever been conducted in this state to determine the presence or potential risk of cytauxzoonosis to the wild or community cat population. In this pilot study, we will survey for C. felis in New York through targeted screening of known natural (bobcats) and susceptible (community cats) hosts. Both archived and fresh tissue samples from natural mortalities of approximately 30 bobcats will be screened by a PCR assay highly specific and sensitive to C. felis. On Long Island, New York, where the bobcat population is absent, we will source community cat blood samples (n=400) through the shelter-based spay/neuter programs. The data generated will provide the baseline required to assess the occurrence of this disease in wild and free roaming domestic felids in the north east. Location data for bobcats and community cats will be combined with ecological data (preferred vegetation, temperature, land use, population density, vector range, etc.) to produce an ecological niche map of NY that will project where C. felis is most likely to occur and the potential risk for transmission to domestic cats. The proposed study is the first step in surveillance for this disease. Information will be shared to increase awareness among veterinarians and pet owners about this fatal disease of cats that is expanding its geographic range to our area.