Yay! I used Trifexis briefly when Interceptor was discontinued, and it worked well for fleas, and the most the dogs tolerated it, but Loomis would vomit daily. Since it wasn't right after his dose, we didn't connect it. The vet suspected Mega-E. We put him through all sorts of testing - bloodwork, barium x-rays, etc and nothing was abnormal. We thought for some reason he had an aversion to dry kibble, so he was on wet food and it seemed to help, but never go away. I noticed when I switched from Trifexis to Sentinel, his vomiting all but disappeared. So, I am super excited about Interceptor coming back. I haven't had a problem with Sentinel, but the less chemicals, the better.