I have a 2 year old Black Swedish duck who lost interest in food and was not acting like herself. We though she looked like she had a heavy 'bottom' area and gave her a warm epson salt soak. Afterwards we noticed a whitish thing at her vent, and I carefully pulled out (what looked like) and egg membrane and small bits of shell. A bit later another membrane was visible and I was able to pull that out too, but it was not a full membrane. We do not have any vets who treat ducks in my area. I do have a new unopened bottle of Penicillin (refrigerated, not expired). It's an injectable and I'm not sure if 1. I should use it and 2. How much I should use / how many days. I would appreciate any help!!!!