What kind of disease do rabbits get in the summer?

Rabbits can go outside in the summer, as long as there's no way they can escape, if you've got a grip of them. If you keep an eye on them, make sure nothing can kill them (sharp things and things they chew on and cats and snakes). Make sure it's not too cold and plenty of grass or soft ground otherwise there is no possibility of you letting them out. It's just too risky.