Please don't give up - he should get there eventually, he is young and everything is so new and exciting to him.
When I first got my rabbits they were a year old, Fenn 1.5 yr. At first she was absolutely fascinated and wouldn't leave them alone every time she went into the garden. She is a gundog and used to bringing rabbits to my OH so I guess them being so near she could not understand why she wasn't supposed to get them for us. The rabbits, even though used to cats, used to thump about in their hutch and run (she used to run round and round the run
) I really thought I would have to rehome the rabbits. However over a few weeks, of telling Fenn 'No' and distracting her she now is fine with them, takes no notice of them in the hutch or run, again just sniffs them if they run about in the garden or when they come in the house, which is something at first I never thought would happen. If she starts getting a little boistersous I again, just say 'No' and she will leave them alone, but the rabbits are now used to her too and just sit there if she comes over and has a sniff. I don't fully trust Fenn if I'm not about, she probably would be fine, but I just wouldn't take the risk and leave them all together but they can learn to live in harmony and him being a baby you probably have more chance teaching him that, in my opinon, than say older dogs as they sometimes get set in their ways.
She still brings rabbits back for OH but seems to know that Ben and Jerry are off limits
.
It does take time, but please stick with it....he should get the message...may take a bit longer because of his age but it can be done....and the novelty will wear off once he knows to leave them be.
I hope it works out x