I now alternate between Advantix and Frontline Plus. One works better on fleas, the other works better on ticks. The fleas here eat Frontline Plus for breakfast.

My sister's 14 month old lab came back lyme positive at her annual visit (as well as her house mate). The dog received all her puppy shots, including lyme vaccine, and a booster at the visit this year. She also used a flea and tick topical last year. She lives in Connecticut. Is this typical and what might cause this?