I had a male American toad named Gremlin who lost the front of his left front foot (all but his thumb and pinkie finger) due to a squashing. He also broke his jaw, which took a long time to heal. I fed him slow-moving foods with extra calcium and kept his water very clean and sanitary until the injury was mostly healed. He was eventually released back into his natural habitat. I second the extra calcium, and I'd recommend slow-moving foods that he won't get too excited about stalking. If he isn't too keen on moving around, just be sure it isn't too warm or too cold in his area, which I'm sure you already know.