I live on a half acre in town. When we first moved here, we didn't have a problem with animal predators, since most people didn't even have dogs, and those who did didn't allow them to roam free. However, we have a railroad track in back of our house that leads to a paper mill that is no longer in operation. Since trains no longer travel on the tracks, fox and coyotes will use the tracks to make their way into town during the night, particularly since there is brush along the sides of the railroad right-of-way. It's not a huge problem yet but I wouldn't let my cats do outside at night anymore.
I haven't seen any coyotes yet but others have reported seeing them along the track, and I have set up wildlife cameras in my backyard that have captured the image of a fox here one night. For cats, raccoons can also be a danger. Not only are the particularly susceptible to rabies but most cats won't stand much of a chance in a fight against a healthy raccoon. Years ago, when I was still allowing my cats outdoors at night, all four of my cats came flying in the cat door one night, followed by a raccoon.