SEROLOGICAL STUDIES ON THE INFECTION OF DOGS IN ONTARIO WITH BORRELIA-BURGDORFERI, THE ETIOLOGIC AGENT OF LYME-DISEASE

A serological study was undertaken to determine whether dogs in Ontari o are being exposed to Borrelia burgdorferi, the etiological agent of Lyme disease. This study consisted of a survey of randomly selected do gs and testing of diagnostic submissions from candidate Lyme disease c ases. The survey of 1,095 dogs, bled between January 1988 and August 1 989, revealed a total of 65 (5.9%) enzyme-linked immunosorbent assay ( ELISA) reactors, of which 22 had immunofluorescent antibody assay (IFA ) titers greater-than-or-equal-to 1:32. All but one of the IFA-positiv e and 10 of the ELISA-positive, IFA-negative sera were further tested by western blot. Eight western blot positive and three equivocal react ors were obtained. Three of the eight confirmed reactors had visited a reas known to be endemic for Lyme disease, leaving five reactors that might have been infected in previously undocumented areas for B. burgd orferi activity in Ontario. Diagnostic submissions of sera from 223 do gs were received between August 1987 and February 1992. Test results r evealed 21 (9.4%) IFA reactors, of which only six had significant tite rs (greater-than-or-equal-to 1:256) and were reactive by an immunodot Borrelia test. All six dogs had travelled to known Lyme endemic areas. Based on results obtained from this study, it seems likely that the a gent of Lyme disease is not widespread in Ontario.