Ivermectin seems to be prescription for pets and over the counter only for livestock. So if you are using cat ivermectin, you need a prescription too. https://

Ivermectin seems to be prescription for pets and over the counter only for livestock. So if you are using cat ivermectin, you need a prescription too. https://news.vin.com/default.aspx?pid=210&catId=-1&id=6018472 https://news.vin.com/default.aspx?pid=210&catId=-1&id=601847... Not sure on the specific differences of horse vs human ivermectin.