Oh you have my sincerest sympathy. We pour hydrogen peroxide into bird (duck) wounds and then put colloidal silver into their drinking water, in a bucket each day. We make our own nano-particle colloidal silver, but you can purchase colloidal silver at the health food store. One teaspoon to a bucket. He won't survive without a companion female duck, though, they get depressed and die.
We keep electric fencing around our poultry yards, although our predator problem is bear, not fox. We'd lose chickens and ducks 3x a year, an entire pen, until we built an electric 'fort knox' fence.