Ticks are one of the most common external parasites to cause infectious disease in our pets. Ticks can carry: Lyme Disease which can be found in every U.S. State and Canadian Province and dogs are 50% more likely to get Lyme disease than humans: Anaplasmosis, an emerging disease, that is surpassing Lyme disease in some areas in North America and very common in Minnesota: Ehrlichiosis is the second most common canine infectious disease in the U.S. (after parvovirus). These tick-borne diseases are very harmful to your pet and usually go undiagnosed until symptoms are present and the pet is already in harm.