Ann,
Yes, the first thing on my husbands list when we move is to install a fence like the one he did here when we adopted Bo ... only thing is, I've heard that gators can actually climb fences!
I don't know which is scarier, gators or snakes but the thought that both are around makes me very nervous and knowing that my sister had a gator at her front door is really scary! They have a six foot wood fence around their back yard for their two English Mastiff's and I doubt a gator would try to climb a tall wood fence but their dogs don't stay out much anyway, they are couch potatoes. I think if they found a gator in their back yard they'd probably install barbed wire at the top of the fence and I wouldn't blame them.
Even with a fence, our Bo isn't allowed out in the yard without supervision because he tends to get into trouble, eating plants and digging holes. When we do move to Sebastian, I will walk around and check everywhere in the yard before I ever let him out! I'm a fussy golden mama to this boy!