Serologic responses to peptides of Anaplasma phagocytophilum and Borrelia burgdorferi in dogs infested with wild-caught Ixodes scapularis.

•Evaluated antibody levels to VlsE of B. burgdorferi and p44 of A. phagocytophilum.•Antibiotic treatment reduced C6 antibody levels within 12 weeks.•Antibodies to the APH-4 peptide of p44 could be detected earlier post-infection.•A. phagocytophilum DNA was detected in peripheral blood 77days post-infection.•Decreasing C6 antibody levels may help indicate control of B. burgdorferi infection.