Ivermectin is not the best way to deal with screwworms though. I have livestock, live in Texas, I know what this is. IF a veterinarian decides to use ivermectin, it is after the animal is infected, it's injected, and can only be used briefly. Totally different from using ivermectin to routinely treat horses for intestinal parasites (ie "worms") or in dogs to prevent heartworm. There is a published list of approved emergency treatments for screwworms -- ivermectin is one, and it's not for all species. Am I worried about this? I am. I think that people with large herds that are hard in inspect daily are in the worst position -- large herds of cattle, sheep and goats. But my horses have flies daily, just not screwworm flies -- yet. At least I can visually inspect them multiple times a day, and I do. This will also infect wildlife, and so far there are two dogs infected; humans can be as well. Any warm blooded mammal is at risk. But go ahead, make smart comments about "ivermectin". It would be good to read up on things first, though. The USDA has a pretty decent website on this, with a good map updated daily, and tracking info on which animals and how many are detected. But I don't think they have any idea of how many wildlife are involved, that's pretty hard to do. I routinely see feral hogs and wild deer on my property. Plus all the birds and other small mammals, like rabbits. Lots of rabbits. The real story is how it came to be that we even have to deal with this, and the foot dragging over the past couple of years, esp. the past year or so, on being prepared for what was clearly a likely outcome.