If it's a sprain, it can be helped by applying an Epsom salt compress to the leg and foot. Soak a clean cloth in Epsom salt and water. Don't let the duckling ingest Epsom salt, it is a laxative. Just wrap the foot and leg and hold the compress on for several minutes a few times a day.
I would follow up with a tiny dab of T-Relief or Comfrey Salve.
I would follow up with a tiny dab of T-Relief or Comfrey Salve.