Very unlikely. It is not at all unusual for a fox or a domestic dog to kill everything in a pen. My neighbor’s dog got into my poultry pen and killed or maimed every single bird, just its idea of fun. There were wings, heads, feathers and legs everywhere. Another dog killed two turkeus, each well over 50 lbs, and didn’t bother eating anything but a mouthful. Canines are like communists, they get very happy and excited when they taste blood, they just can’t control themselves, all restraint disappears.
Well, we’ve had rabies in a fox very recently in DC; so I wonder.