Molecular Detection of Vector-Borne Pathogens and Their Association with Feline Immunodeficiency Virus and Feline Leukemia Virus in Cats from Northeastern Thailand

In Thailand, domestic cats are frequently exposed to vectors that transmit a variety of pathogens. In this study, the prevalence of vector-borne pathogens (VBPs) and their association with feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) were investigated in 187 domestic cats from animal hospitals across five northeastern provinces. Twelve pathogens, including viruses, bacteria, and protozoa, were screened using PCR assays. FIV was identified in 2.67% of the cats, while FeLV exhibited a notably higher prevalence of 29.95%. Among the bacterial pathogens, <i>Bartonella henselae</i> was the most frequently detected (94.65%), followed by <i>Rickettsia felis</i> (34.22%). Protozoan infections such as <i>Babesia canis</i> (8.02%) and <i>Cytauxzoon felis</i> (3.21%) were less prevalent. Co-infections were common, with numerous cats hosting multiple pathogens. Correlation analysis revealed moderate associations between FIV and <i>Babesia microti</i> (r = 0.43), <i>Babesia canis</i> (r = 0.35), and <i>Mycoplasma</i> spp. (r = 0.33), indicating potential co-infection or predisposition. Although significant differences in the total white blood cell counts were not observed, leukopenia was more commonly found in FeLV/FIV-positive cats. These findings indicate that a high burden of infection and co-infection exists in the feline population, supporting the need for expanded pathogen screening and enhanced vector control strategies.