We have three Nigerians that we have found have lice. Our vet told us to use Frontline Lice spray for dogs on them. I was able to find Advantage spray, and was wondering if anyone has used this before.
I would suggest trying a good heavy application of Diotomacious Earth before trying something toxic like a lice spray. DE works fast, is non-toxic, won't contaminate feed or water sources and is safe enough to eat.
Using Diatomaceous Earth is a very good idea for all the reasons mentioned by Craig, and yes, it is very effective against lice. We got a dog that had some kind of mange (a type of lice infestation) and used food grade DM on her. It did the trick beautifully, cheaply, and without any toxicity to her. And if you have any other goats or animals, I would put some DM on them also in case some lice migrated which could certainly be the case.
External parasites can be a sign of mineral imbalance. Are you giving them minerals specific to your location or just generic ones? Free choice? Any changes in the colour of their coat? This can be a sign that something's missing from their diet (or too much). The mineral needs can change with the season.
Most parasites can be managed by diet and environment. Other times, they are an indication of an underlying condition. Treat that condition, and the animal becomes healthy enough to fight the bugs.
I very seldom use toxic ick on my animals because the risk of having resistant parasites from using the chemicals is too high. If I have to use the chemical, I want to be certain it is going to work first time. But it's been years since I needed to. Prevention is much cheaper and easier on the animals.
you can also use mineral oil or even vegetable oil to get rid of lice, just coat the animal liberally and they will die. Be sure to continue the treatment until all the eggs have hatched out so there isn't a re-infestation.