It is correct that botulism is more common in warm and hot climates, but with the recent weather changes and the story of your pond, what could have happened is this: Something died in or at your pond and was covered in ice, therefore deprived of oxygen. The botulism bacteria thrives in oxygen deprived environments so it had an advantage over other rotting organisms and outgrew those. Even with slow growth due to the low temperature, given the advantage of an oxygen free environment botulism bacteria will thrive. Then the weather changed and the ice thawed and the ducks found whatever died there…
A similar thing happened to my drake Limpy in Summer 2018 and for three days i thought he would die. He survived but kept some neurological damage to his legs. He is walking a bit stiff and sometimes he stumbles.
Here is the link to the post in the Limpy-Thread which summarizes the treatment:
Limpy Treatment
We gave him a lot of pills to swallow and here is a video how to give a pill to a duck:
How give a pill to a duck
Good luck! If she makes it through day three the chances for a more or less full recovery are good.
