Somthings wrong with my duck

[CurrentWave]

My full grown duck keeps getting up and falling over. Also it keeps opening and closing it's mouth. The duck is eating and drinking just fine. I let my ducks free range. They have a spring fed pond to swim in. I feed them peas with rye and alf pellets with minerals in molasses and vinegar pored over it.


Any ideas on what's wrong with my Duck?



Thanks Ahead