In veterinary medicine there is extensive testing of dogs for exposure to Borrelia burgdorferi and Anaplasma. This has allowed for compilation of data that shows where the risk for exposure is greatest and the ability to predict risk for future exposure. Fortunately, most tests also test for heartworm disease, which is important because people will test their dog for heartworm in areas where Lyme disease has not been prevalent before, and because the test checks for several diseases at once, new areas where Lyme disease is spreading can be detected early. The Companion Animal Parasite Council website has several useful maps that provide historic and real time testing results, as well as predictions for 2019. The 2018 data can be found at https://www.petsandparasites.org/parasite-prevalence-maps/#2018/all/lyme-disease/dog/united-states/