The company data shows a 3% chance of contracting lyme on dogs treated monthly (& correctly) with FL. You have to weigh your risk with the data and make a choice for your comfort level.
We currently use Frontline and Lyme Vaccine as in the past 17 years with our Field Work we have had 2 dogs positive with Lyme's. We live in Southern New Jersey.
50% of our dogs in the Boston area, with supplemental treatments of the perimeter of our yard. We routinely give doxy caps 2x a year to all of our dogs now.
Treating a dog with suboptimal doses of any antibiotic, particularly for a disease it may not have, is exactly how we end up with drug resistant bacteria.
When that happens, everyone loses.
Bonnie
PS - I do semi-annual Lyme Titers and do monthly frontline, 12 months a year. I have one dog with Lyme Disease - nasty little recurrent disease.
I use Frontline every three weeks all year round. I do field training with two of my dogs and I've had good luck with Frontline. It's very important that it be applied directly to the skin. I vaccinate my 3 dogs with the Lyme vaccine yearly and I also do a 4DX yearly. One of my dogs was diagnosed with Lyme 6 years ago and has had 2 flair ups since then. I treat with Doxycycline when she has a problem. The over use of antibiotics is NOT good medicine.
I use frontline monthly, and add in the frontline spray 2 weeks into the frontline dosing.. in the bad tick months, all 3 of my dogs are vaccinated for Lyme, and I have the only 3 dogs in the neighborhood who are negative for Lyme disease.