Lice are really hard to see with the naked eye...I'd suspect fleas since they fell off, ticks will generally be attached and require removal.
I know someone who gives a brewer's yeast tablet every day and reports great results. This may not be effective if you live in a hot humid area.
Flea sprays are ineffective at preventing fleas.
I use frontline on all four of mine...no ill effects and no fleas either.
__________________ Deb, Reese, Reggie, Frazier, Libby, Sidney, & Bodie |