The time for lice seems to be late winter, or early spring. In the summer time, shaving down a goat’s coat and letting the sun beat down on the buggers is usually all it takes to get rid of an infestation. However, if you have lice in the winter or spring, you will want to treat. Lice are not life-threatening to healthy goats, but they are uncomfortable for the goat, and irritating for their skin. Lice can also cause hair loss and attribute to anemia.
Diagnosing lice is more symptomatic than anything. An itchy goat with a rough, patchy coat is one indicator. If you part their hair, especially the hair along their back, you will see small yellow or brown creatures, like living hayseeds, with red heads. The biting lice will scurry out of your way, the sucking lice will be latched on.
Now that you’ve identified them, it's time to find an effective treatment that not only repels the lice, but also prevents the eggs from hatching and/or thriving.
Nits, the lice eggs, hatch about every seven days, so treatment should likewise be repeated every 7 to 10 days, until no signs of nits or lice are present.
Nits that fall from their host will most likely never hatch, and if they do, they only have a few hours to live if they can’t find a food source. Full-grown lice can only live about 24 hours without a food source.
Mode of destruction
Equisect fly spray (tried it, originally successful): Spray the Equisect onto a horse brush, then brush the goat's body down to the skin, against the grain. Repeat every 7 to 14 days, as needed. It is a softer chemical than Ivermectin, but I would be careful not to spray it directly on plants as it can have harmful effects on beneficial insects. This treatment worked excellently for a couple of years, but now I believe the lice have grown resistant to it.
Diatomaceous Earth (tried it, helpful): An all-natural dust. Make sure to buy the food-grade DE, and be careful that you and your animal breathe in as little of it as possible. DE will attach to the exoskeletons of parasites. This is the preferred method for kids, though it may take longer. I found it more effective in preventing lice from spreading to uninfected goats, than as a treatment.
Sulfur Dust (tried it, helpful): Less of a risk to breathe in, and I've found it effective. I dust all of my herd if anyone is showing signs, and then repeat in seven days. I also dust the bedding. Lice hate sulfur, and I've found this even more effective than the chemical treatments. During the colder months when I can't shave the goats, this is how I treat my herd.
Shaving (very effective): In the spring or summer, the perfect solution. Nothing to hold on to or to protect them from the sun, and the lice cannot survive. This eliminates the need for chemical treatment, and cuts off the cycle all together. After shaving, clean out all the old bedding in their barn.
So there you have it. These creatures are anything but indestructible. Pain as they are, there will be nothing quite as satisfying as when the treatments are over and your herd is no longer uncomfortable and is growing back their beautiful coats.