Ducks keep dying
We are new to raising ducks and need help since we've started loosing 1 every month or two.
We have 2 flocks of about 8 birds each and are only loosing them from one.
First the duck will have trouble walking, then can't walk much, then not at all, then dies. Still eats and drinks water till the end. Sometimes pure white secretion from the eyes, looks like foam.
Only major difference between the 2 groups of ducks is the dying ducks sleep in a screened duck house with a non-slip
Formply floor that is scrapped clean every day and the healthy ducks are in a chicken tractor at night that is on a 30mm large gravel driveway.
Dying ducks also share duck house and pen with 5 chickens.
Also the dying ducks water is in an old cast iron pot vs. healthy ducks have plastic tub. I since changed the cast iron pot to different pot.
Any help is much appreciated.