Are there little white eggs in the hair as well? Check under the forelock and in the whorl on the flank. This appears to be lice's favorite place to lay eggs. But anywhere that is constantly warm and hairy goes really.
There are spesh shampoos to treat lice and treatments where you place a chamical 'blob' on the neck which is absorbed into the skin and kills the lice when they try to feed. I used the chemicals because it was too cold to wash the horses last year when a horse i was working with got lice.
Also treat grooming equipment and rugs because they can linger on them after treatment. wash then put outside in the cold for 2 weeks
We lose ourselves in the things we love, we find ourselves there too ~Kristen Martz