All my rabbits are outside during day, and currently 20 of 22 in hutches during the night, the other two in the house. It really depends on local climate and fauna what measures need to be taken - although there are some kind of botflies native here flystrike in rabbits is pretty much unheard of here. Actually, the only Issue I had in 9 years were ear and fur mites, each once, and easily treated. No coccidosis whatsoever, seems climate here doesn't support it.
I don't even have a real fence apart that around the hutches, wouldn't do much good against foxes and marten anyway. And with lots of predators and no wild rabbit population I'm pretty lucky regarding diseases, here in a small side valley between alps and balkan.
I lost one buck after an fox attack 5 years ago, didn't get him, but due to shock, and that fox also got 4 growouts out of a hutch while I was in the US over christmas, well, that mange ridden fox is history now. There is the risk that something like that happens again, but I chose to live with it, and react when problems occur.
A wildlife camera placed around the property to see what is sneaking up is the most useful tool ever.
