My vet still gives Frontline Gold. I asked about the pills and he said he would prefer to keep my dogs on Frontline, I didn't ask why. I wonder if this is the reason. No problems with the Frontline. Some say it no longer works, but it does on my dogs. Wonder if the Gold is different than the plain Frontline..my theory, if it ain't broke, don't fix it.
Frontline has been out of favour with vets here in UK for several years, mostly. I think, because it's lose of efficacy. Most seem to prescribe advocate now which seems ok - been using it on our various dogs for 2-3 years. It's made by Bayer so is probably available in US