They can catch lice from any kind of animal, be it birds etc
The eggs are layed on the coat and usually hatch out within 10 days.
Apparently they like the comfort of long hair, and during the winter months their numbers build up, so they are at their highest in the early spring.
Its recommended that coats are clipped and to break the two week cycle that lice have you should wash the coat with a insecticidal shampoo or thoroughly dust with lice powder.
You can also buy some wormers that have "ivermectin" in these have a useful side action of killing lice.
Check with your vet first though, before using the wormer. :)