Posted late last bread.
Not a skilled digger but dug quite a bit. The main thing for me is the logic of it. Ivermectin kills parasites in bodies. Horses, cows, humans. Malaria is a parasite. It all fits perfectly. Will do more digging when I get back.
They don't have to kill the parasites is cattle. Just give them a vaccine. They only live 2-3 years before slaughter and dinner tables. Same thing with chickens. Horses? Different story.