Preventive Veterinary Medicine Graduate Group (MPVM)

This retrospective study evaluated Bartonella infections in 1,609 dogs and 740 cats, suspected to have been exposed to ectoparasites (mainly fleas, ticks) or presenting with symptoms associated with tick or flea-borne pathogens tested by a national reference laboratory across the United States from 2008 to 2018. Bartonella seropositivity was 10.8% in dogs and 5.81% in cats, indicating significantly higher odds of infection in dogs (OR = 1.97, 95% CI: 1.39–2.78, p < 0.001). Geographical analyses highlighted significantly increased risks in the Northeast and South relative to California. Logistic regression analyses revealed significant seasonal (April–June) and temporal (2016–2018) variations in seropositivity. Multivariable logistic regression showed no statistically significant associations with sex, age, or neuter status in either species, though trends indicated potential seasonal effects. Low predictive power (AUC ~0.58) suggested additional factors are needed to improve understanding and prediction of Bartonella infection dynamics. Despite these findings, the study faced limitations such as potential geographic sampling bias, incomplete information on vector exposure, and limited details on animal lifestyle. Future investigations should address these gaps to better clarify Bartonella infection dynamics and further elucidate the public health risk posed by zoonotic Bartonella species.