all depends on the maturity of the dog, all breeds of dog mature at different rates, i personally started my first working lurcher a beddy cross at 7 month old on a few easy rabbits, picking his runs so that he was almost guarenteed the catch so to speak, id only run him on rabbits that are squatted or if you do a bit of ferreting or know anyone tht does, get ya sel out with them and let the dog have a go at some rabbits that have been netted but obviously letting them go in the middle of a field first. all the best mate