From 2001 to 2009, nearly half the states in the U.S. reported over 500 dogs infected with Lyme disease.
States in the Northeast and the upper Midwest — Minnesota, Wisconsin, Illinois and Michigan — remain at greatest risk. Other states like Florida, Texas, Nevada, California and Oregon remained in the 500-plus category.
Veterinarians practicing in Lyme-endemic areas can experience up to 73 percent of dogs testing positive for Borrelia burgdorferi infection, the pathogen that causes Lyme disease.