Pet ownership increases human risk of encountering ticks.
We examined whether pet ownership increased the risk for tick encounters and tickborne disease among residents of three Lyme disease-endemic states as a nested cohort within a randomized controlled trial. Information about pet ownership, use of tick control for pets, property characteristics, tick encounters and human tickborne disease were captured through surveys, and associations were assessed using univariate and multivariable analyses. Pet-owning households had 1.83 times the risk (95% CI=1.53, 2.20) of finding ticks crawling on and 1.49 times the risk (95% CI=1.20, 1.84) of finding ticks attached to household members compared to households without pets. This large evaluation of pet ownership, human tick encounters and tickborne diseases shows that pet owners, whether of cats or dogs, are at increased risk of encountering ticks and suggests that pet owners are at an increased risk of developing tickborne disease. Pet owners should be made aware of this risk and be reminded to conduct daily tick checks of all household members, including the pets, and to consult their veterinarian regarding effective tick control products.