“One monthly flea treatment for a large dog contains enough imidacloprid to kill 25 million bees, according to recent research. Avoid them altogether, or if you absolutely must de-flea, don’t let your dog swim for at least a month after treatment.”
https://www.theguardian.com/environment/2025/jun/17/insects-dying-25-easy-and-effective-ways-you-can-help-aoe #DogsOfMastdon