Bartonella spp. seroepidemiology and associations with clinicopathologic findings in dogs in the United States.

BACKGROUND Improved understanding of Bartonella spp. serology in dogs may aid clinical decision making. OBJECTIVE Describe demographic and geographic patterns of Bartonella spp. seroreactivity in dogs, and describe hematologic and serum biochemical abnormalities in Bartonella spp. seroreactive and nonseroreactive dogs. ANIMALS Serum samples from 5957 dogs in the United States, previously submitted to IDEXX Reference Laboratories. METHODS Serum was tested using 3 indirect ELISAs for B. henselae, B. vinsonii subsp. berkhoffii, and B. koehlerae. Complete blood count and serum biochemistry panel results were reviewed retrospectively. RESULTS Overall, 6.1% of dogs were Bartonella spp. seroreactive. Toy breeds were less likely to be seroreactive (3.9%) than mixed breeds (7.5%; adjusted odds ratio [aOR], 0.48; 95% confidence interval [CI], 0.32-0.72), and dogs <1 year old were less likely to be seroreactive (3.4%) than dogs 1 to 5.5 years of age (7.3%; aOR, 0.42; 95% CI, 0.23-0.72). Dogs in the West South Central (9.8%) and South Atlantic (8.8%) regions were more likely than dogs elsewhere in the United States to be seroreactive (aOR, 2.22; 95% CI, 1.31-3.87; aOR, 2.44; 95% CI, 1.38-4.36). CONCLUSIONS AND CLINICAL IMPORTANCE Demographic and geographic findings for Bartonella spp. exposure were broadly comparable to previously reported patterns.