I'm interested in what many of you use for flea and tick prevention. I started using Frontline last year April through November and it has worked effectively. I've used it in previous Shelties without an issue. Now, my vet wants me to use Simparica. What flea and tick med has been found to be the safest for shelties? I remember Heartguard was not to be used years ago. With Simparica relatively new to the market, there are no long term studies and that concerns me but there are plenty of dogs adversely affected by this new drug. I really wish there were a safer alternative but living in a tic infested area and plenty of wildlife, including deer, I feel I don't have an option. Thank you.