We're currently camped at the SE Orlando/Lake Whippoorwill KOA. My dogs actually SQUEALED as we walked towards the dog park - they remembered it from last year. Clearly a version of Disneyland for dogs? 7500 sq ft of fenced off-leash paradise, complete with courtesy tennis balls and frisbees; poo-bag stations; and fresh water for drinking... after tearing around for a bit, I'm able to walk my dogs over to the boat ramp to let them wade and cool off. There's also nice hiking trails for on-leash walks.
We humans love the tropical feel of this beautiful place, too. It's not the cheapest, at $50+ per night; but we ALL really love this place!
