We have a young goose - maybe 2 months old or so and he acts like a young foal trying to walk. Husband found him in the yard upside down and brought him inside. Kept him on the porch for a day or two - gave him vitamins and put him back out - he went upside down again and couldn't turn over. He acts fine and healthy - except for being unsteady on his feet (like a human having a case of vertigo) and falling over and not being able to get back on his feet under his own power. Suggestions on what is wrong and how do I treat him?