[Ellie May]

I use Frontline Plus only if it is absolutely necessary after a Dawn bath.
I also would consider Advantage and Sentinel depending on our needs at the time because they don't all actually kill fleas. Ticks are not an issue here.

I do not like Revolution for the reasons stated above and would not trust it for heartworm protection.

Comfortis is probably fine but it is very new and I would like to wait longer to see reaction reports.

Advantix contains permethrin which I try to avoid but it may not be avoided if you have ticks.

The things used in natural products can cause side effects too and I just don't trust them. I'm sure there are a few good ones out there though.