Ticks are gross. They belong to the same family as spiders, but unlike spiders, don't seem to have any other function than to freak people out and cause disease. There are seven disease-transmitting ticks in the United States and Madison, Wisconsin is home to four of them: American Dog tick (Demacentor variabilis), Blacklegged tick (aka. deer tick or Ixodes scapularis), Brown Dog tick (Rhipicephalus sanguineus), and Lone Star tick (Amblyomma americanum).
The deer tick (Ixodes) gets the most press, as it transmits the spirochete bacteria that causes Lyme disease. It also can transmit Anaplamosis, Babesiosis, and Powassan diseases. But the other three ticks aren't inocuous. They can cause Rocky Mountain Spotted Fever, Tularemia, and Ehrlichia, all of which can cause severe disease.
The best defense against tick-borne diseases is to prevent ticks from attaching to you and your dog in the first place. There are a lot of different acaricides on the market now, but not all of them are very effective. One of the first products on the market was Frontline. It was a great product when it first came out, since there wasn't anything quite like it and it was much more effective than anything available at the time. But studies have shown that Frontline doesn't have good efficacy for a full month. In fact, by day 21 after applying it, ticks may still fall off the dog and appear dead, but they are really just "zombie" ticks and will "reanimate" a few days later. If they dropped off in your house, you will have live ticks crawling around, looking for another blood meal!
The new oral medications (Nexgard, Bravecto, and Simparica) are more effective and last most of the month. They each have their pros and cons and none are perfect. Nexgard is the safest of the three and can be given to puppies. But it has the slowest speed of kill, which could allow feeding ticks to transmit Anaplasmosis and Ehrlichia (these bacteria hang out in the ticks salivary gland and can be transmitted within 24 hours). Bravecto lasts a bit longer, but has more side effects and can't be given to puppies. Simparica has the fastest tick kill of the three, but has the most potential side effects and also can't be given to puppies.
There are also newer, more effective topical medications (Vectra 3D) and the Seresto collar, which can last 6-8 months. I highly recommend talking to your veterinarian about what is best to use on your dog (and cat) and not just buy the cheapest product from Costco or a pet store.