Seizures in a Pekin duck

Any thoughts? My 11 week old Pekin has had 2 seizures today. My other 3 Pekins are fine. Not sure what could be causing this. The only thing different was that on Tuesday one of my Pekins was in water that my 2 khaki campbells and my rouen had been in. These ducks were purchased 2 weeks after the Pekins and have pretty much been separated. We have slowly been introducing them to each other so there will be no issues when they are moved to their new duck house. Now, I am worried that my Pekin picked something up from them in the water. Nothing else has changed. The other ducks did have one rouen duckling who died looks like she suffered from some sort of neurological issue because she had no balance and would stagger from side to side. However, the Pekins were never around her and the ducks purchased with her are fine. Please help with any advice.