I Found A Single Lice On My Scrotum Thismorning, Ive

I found a single lice on my scrotum thismorning, ive started working at a hotel and we all share a washing machine can they b contracted this way? Also i was playing with the groundskeeper s dog can they be contacted this way? I haven't slept with anyone so im at a loss, although I see no other signs or symptoms of any more lice