Hi! We purchased two ducklings about 3 weeks ago. They are a little over a month old. One is perfectly healthy but the other is constantly quivering and when it stands it’s chest, compared the the healthy duckling, looks caved in. It is eating and drinking. My husband when out and bought electrolytes for the water and food with a lower protein percentage. Any thoughts as to what might be wrong with it? Or does anyone have any other suggestions?