The increasing risk of Lyme disease in Canada

Abstract

There is an increasing risk of Lyme disease in Canada due to range expansion of the tick vector, Ixodes scapularis. The objectives of this article are to i) raise public awareness with the help of veterinarians on the emerging and expanding risk of Lyme disease across Canada, ii) review the key clinical features of Lyme disease in dogs, and iii) provide recommendations for veterinarians on the management of Lyme disease in dogs.

Figure 1

Surveillance for Lyme disease risk areas, and tick vectors in eastern and central Canada based on different surveillance systems: A — Active surveillance sampling sites visited from 2003 to 2012: site locations that were sampled are delimited by grey lines (buffer of 25 km created around each site) and the sites with at least 1 I. scapularis tick found are represented following a colored gradient and quintile classification (darker areas indicating higher numbers of sites with ticks). B — The geographic distribution of I. scapularis ticks submitted from dogs based on the probable locations of acquisition, 1991 to 2012: the locations with ticks submitted are represented following a green gradient and quintile classification (darker green areas indicate higher numbers of locations with ticks submitted). C — The geographic distribution of I. scapularis ticks submitted from humans based on the probable locations of acquisition, 1991 to 2012: the locations with ticks submitted are represented following a brown gradient and quintile classification (darker brown areas indicate higher numbers of locations with ticks submitted).

Figure 2

Lyme disease risk areas (hatched areas) where surveillance and research studies (risk mapping in BC: http://www.bccdc.ca/NR/rdonlyres/A07283DB-A709-4494-BFD5-E2AB7ED2724C/0/Lyme_Disease_Risk_Areas_Map_BC_June_2013.pdf) suggest ticks and B. burgdorferi have become established.