My Brittany was treated with Noromectin, 6 mg of a 10% solution. He had severe ataxia and I believe very nearly died of his reaction to the drug. I would suggest great caution using this drug. While the vet said that it is generally herding / collies that have the genetic difference that allows it to cross the blood brain barrier, she said all dogs are unique.
I'd suggest checking for sensitivity before giving a dose of this stuff. Cooties don't kill overnite. I think this could.