We had several calls this spring about baby foxes that were orphaned because their mothers were shot, usually by a neighbor or acquaintance of the finder. One of the most common reasons the shooter gave for killing these animals out of season? “I didn’t want it to kill my dog.”
Foxes are far too small to prey on a dog, or even a cat. There are a few cases of foxes fighting with cats or dogs— occasionally leading to the death of one of the animals— but these cases occur exclusively when the fox gets cornered by the pet and lashes out in defense. A red fox is naturally shy and nervous, and enjoys a diet of mostly small rodents, with their largest typical prey being rabbits and small chickens. Foxes have a natural instinct to avoid preying on other carnivores, including cats and dogs, because it’s extremely dangerous to them.
It’s always a good idea to keep pets properly contained to avoid confrontations with wildlife. But your dog is much more likely to get killed by a crow or deer than a fox.