Hi! I'd just like to know what you use for your dog's flea & tick/heartworm medication. I myself used to use a combination of Heartguard and Frontline, but when we had a flea problem and the Frontline wasn't doing its job, I switched to Trifexis (about 6 months - 1 year ago). However, I'm hearing a lot of horror stories about Trifexis on the net and especially on Facebook. I'd really like to hear your opinion on this - is it just hype or is there a real danger? Thanks so much!