Did you stick your finger in the water? I once had a de-icer that got a short and electrified the water.I have a small bucket de-icer (about 5 inches in diameter) in the water bucket that i keep with the feeder for my chickens and ducks, and another water bucket out in the outer run that freezes and that i refill daily. For some reason, NOBODY will use the bucket with the heater in it.... i can’t figure out why. It sits on the bottom, it’s not floating,
Other than the one shocking incident, I have never had an issue with animals caring that a de-icer was in the waterer.