We found four or five fleas on my dog, he is treated with frontline monthly, and my mom treated him again once we noticed the fleas. My question is how much should I worry?

Should I treat the bunnies with Advantage or Program (I think those are the bunny safe ones) I know not to treat them with frontline. 

What should we do to prevent a full blown flea infestation, or do we not have anything to worry about because my dog did have frontline on when we found ticks on him?

I just don't know how many measures we should take.

Thanks for any advice you can give me.

I think it would be fine to treat the buns just as a precaution - I'm not familiar with Program, but I do know Advantage and Revolution are safe.