I know other folk have there own methods but i don't give mine the opportunity to see rabbits at five months, and i really wouldn't worry if the pup shows no interest in chasing at that age. I used to take a pup on the lead during sessions and he saw older dogs chase and catch and displayed nothing but a mild interest and no desire to join in, he was around 12 mths before he clicked, and went on to be a very usefull all rounder whos abilities in certain areas outshone my older dogs.............