No, only the dosages meant for animals were calculated for animals and people should not try to use Ivermectin containing medicines intended for animal usage.The issue with Ivermectin is that dosages have been calculated for animals, mostly sheep and cattle. Because there have been so few successful human trails, there is no recommended human dosage. Whomever takes it will probably kill themselves when they take the dosage meant for a cow or for a sheep for that matter. If you take too little it won't work. Whomever is dosing themselves with the stuff is doing a backyard (unscientific and untested) dosage calculation.
There is a variety of products containing Ivermectin intended for human consumption and Ivermectin is considered very safe in itself.