To be fair, this is not entirely the case in the linked article: > Ivermectin is a deworming agent most commonly used on horses, livestock and occasionally dog

To be fair, this is not entirely the case in the linked article: > Ivermectin is a deworming agent most commonly used on horses, livestock and occasionally dogs and cats. It is used in smaller doses in humans as an anti-parasitic, to treat conditions including skin problems and headlice.