That's TERRIBLE ! Does she know Fleas can KILL A DOG if left untreated ? WHY do people get pets then totally ignore the BASIC Care and needs ?
Frontline is a good flea remedy but she's going to need to treat her whole house to get completely rid of them - that's just nasty she didn't treat her pet and home. That poor dog must be miserable.
Sorry - I don't want to be rude about your friend but she's not a very nice person letting her dog be riddled with fleas