Frontline flea treatment?

Frontline is supposed to control fleas for a full month, so chances are your dog will be fine for now (although it isn't unheard of for a treat treatment to fail). However, if her dog was in your house/yard, then it's not unlikely that there are some fleas in your house/yard now. When the Frontline stops working in a few weeks, and if there are indeed fleas in your house, those fleas will go for your dog.

It could happen. I cannot remember which flea/tick treatment is which, but the treatment either kills the egg stage or the adult stage. Either way the dog has to get fleas in order for the medicine to kick in. If the adult stage is attacked, it requires the dog to be bitten by the flea compared to the egg stage getting killed.

Personal use of Frontline has not been great and I personally didn't like the way it worked. If your dog does get fleas again and they do not go away, go talk to your vet. Even ask about the pill used to kill fleas (it's like magic, really) and perhaps recommend it to your friend with the heavily infested dog.

If your dog does contact fleas, you need to throw dog beds in the wash with hot water, as well as rent a carpet cleaner that uses hot water to clean.

Most likely not but you should treat again in 2 weeks to make sure there are none in the environment that have hatched.

spray your dog with like the frontline spray thingy...just for extra precaution :D