Fig. 3

Evidence of antibody to Ehrlichia spp. in dogs by county, grouped according to percent positive tests. Few results (< 30 per year) were received from counties shaded gray, precluding interpretation of the presence of antibody in dogs from these areas. Counties with at least 210 results available for the 7-year period were shaded according to the following code: no dogs reported as positive (0%, white), 0.1–0.5% (light purple), 0.5–1.0% (purple), 1.1–2.0% (dark purple), and > 2.0% (very dark purple).