well like the man said, But also give it time! some lad's rock the lamp to help the dog see, but i find the rabbits moves if you do that!!
So i hold the beam on the bunny till she saw it, or the other thing you can do, is try to get the rabbits to move and get the dog to watch it run!! best do that at 1st, and not on the land you hunt,as you'll get them lamp shy!!
I've done that on land with foot paths on, but no good for running dog's and + a anti slag is the owner!!