Okay, in case anyone comes back to this, here's what the vet said:-
No, there's no risk of your home getting infested with ticks as it could with fleas. Ticks won't survive indoors, so when they drop off they will die. The best thing to do for the dogs is to keep removing them as you find them, and eventually they will all go. There is no treatment that will kill them all on the dogs.
In future, before going to a tick infested area, consider treating them with a preventive product such as Advantix, which should prevent the ticks getting onto the dogs in the first place.
(Oh yes, and a bit of advice about Lymes disease, but iwon't go into that as its been well covered here on a number of earlier threads.)
Edited: 31/08/2008 at 11:44