If I was gonna build one Id want it to be at least 5 acres and more would be even better.
I wouldnt think you could run a pack of dogs for very long even in one that was 5 acres without running the rabbit down. It would work to solo or brace some in though or to start puppies.
Jeff Williams in E. Prairie, Mo. starts and conditions dogs too. He charges $75 per month and with as much running as he puts on em, thats a deal. Plus, he can show em more rabbit tracks in a months time than I can in three months.