Oh, no. The poor mosquitoes. They give this stuff to horses. It can't be too dangerous, given how expensive the things are. It's used in horses to kill the larva that botflies lay in them, and given to dogs to prevent heartworms. My best guess is that the next big "pandemic" vector will be an insect or parasite of some sort, and they don't want anyone using ivemectin regularly, because it will disrupt the spread.