My mom uses Trifexis on her dog with no problems. I don’t use any chemical flea and tick medication on my dog, only natural. I have been using diatomaceous earth along with Ark Naturals Flea Flicker Tick Kicker for 2 years and my dog has never had fleas or ticks. When I was poisoning her with Frontline she had ticks all the time. As far as heart worm medication goes, I follow a map that I found on Dogs Naturally Magazines website. It shows the states that you live in and when to start and stop the medication. The temperature has to be above 57 degrees F for 14 days for it to be possible for a dog to get heart worms and if it falls below 57 F the cycle is broken and starts all over again. I will look for the article and put a link here. For the few months that I need to give heart worm meds, I give Heartguard. It does make my dog a little sick for a few days so I give it to her every 45 days. The strength of the medicine is still at 99% at 45 days.
