When to frontline? Can anyone give me the instructions?

[Coco]

Wherry has picked up fleas 3 days ago. She was only frontlined recently (with 'spot on' (?), the neck drop one whatever it's called) so my question is should I leave the previous dose to do it's job and hopefully kill them or give her another dose? I don't have any in at the moment and the website doesn't seem to say.
I don't want to do it unnessicarily but then I don't want them to spread and get all over the house?

[Nicola]

When did she have the spot on? If she still has live fleas on her now and they don't seem to be dying off then I'd definitely get something to treat them pronto, they are prolific little beggars and will lay eggs in carpets and upholstery and then keep reinfecting the dog plus it's probably not very pleasant for her either. I use the Frontline spray rather than the spot on though so I don't know what the exact recommendations are with it, I use the spray as I can do 'touch ups' as and when required.

[Coco]

She had the spot on as a precaution about a month ago ish. She picked the fleas up 3 days ago after being at my aunt's I think or it could have been from another dog on a shoot the next day. If they are from my aunt's they could be from the cats. She is usually flea free, i'm just worried, as you say, about them getting in the carpet etc. Perhaps i'll get some spray in and give her a little shot. They aren't exactly rife, just the odd few at the mo so i'd rather nip it before they spread.
I know Damien Rommel's Dad swears by the sea as a cure and we may be off to the coast tomorrow so if we make it i'll let you know how the salt water treatment goes.
Thanks

[*Jay*]

Frontline can be re-applied every 4 weeks

[angelbaby]

Quincy was doubled dosed when he was riddled with them a while back, he had the spray on at the vets but it was a bit plop really so got the pipette ones for him couple of days after that spray one, the vet said it was fine.  Do him every month now, but i get the house spray one to use occasionally, never had a flea on me!