Heartworm prevention should be started June 1, 2014 and given monthly through November 1, 2014. There are many cases of positive Heartworm dogs in Minnesota. Heartworm is transmitted by mosquitoes. If you need Heartworm prevention, please call our office at 218-722-3963. Flea & Tick prevention should be applied monthly. We have a variety of Flea & Tick topicals (Parastar, Vectra 3D and Frontline Plus) available. Please call our office for a recommendation for your pet.