thanks for your comments. the dog is about two your old and meant to be working rabbit and fox only bean out with him once, he was very keen and flu down the hole, after a bout 30 seconds he started to open up, edging back and forwards and then went quiet, the dog came out of a bolt hole in the cover witch we did not see. there was a good chance it bolted, so we tried two more places, the dog went straight in and opened up in both of them, but did not stay down for long, we had a 100 % fox dog to check to holes, went down so there must of bean fresh sent in there but there was nothing in them,