Black Oil Sunflower Seeds and Pine tree branches work to keep the worm load down. But I wouldn't just feed them that, because its not enough. Thats about as Natural as it gets altho there are "natural wormers" in a liquid form. We don't use those because we don't really believe they would keep the worms down in our area. (Too wet) We did buy a natural wormer once called Ex-pel (or X-pel, not on hand) but we never tried it. Paid a lot of money for it too.
Sorry I don't have any websites. But if you go to Fiasco Farms, theres some natural wormers on there. It works for them but what may work for them, wont really work in other areas.
Orrr. A natural wormer would be kiko goats! Just kidding, even though they are naturally resistant to worms, they still need to be wormed, but not as much as other breeds.
I use Mollys herbal formulas which on the Fias Co Farm website that Tyler posted. It comes with 2 formulas that work in conjuction with eachother. They take a lot of dedication & have to be given weekly. I mix the correct amount of formula with just enough water to make it suck into a syringe (with no needle) & squirt it into the goats mouths. Some of my goats hate it, and some seem to think it's a bottle of warm milk waiting to be gobbled down lol! I have another friend who uses it with great success & she mixes something to make little balls as "treats".
I use pure, food grade DE as a parasite preventative for all my animals, goats included. There are studies showing its efficacy in pest management but what matters to me is how it works for me. And in the 20 some years I've been using it in/on dogs, poultry, waterfowl and sheep, we've never had a worm or external parasite infestation.
For external parasites, on goats I dust it into their fleece. As a worm preventative, I add a cup and a half into 50 lbs. of goat chow/pro manna senior horse pellets and mix it well.
I am weary of having to provide any wormer on a regular basis because any worms in the goat's system WILL develop a tolerance for it. But, some natural ways to help keep the load down so you don't have to worm medicinally too often would be, as mentioned, pine trees, pumpkin seeds, black oil sunflower seeds, and copper, provided either at an ideal level daily or as a bolus on a schedule that suits your areas deficiencies. If you provide some or all of these things, maintain a clean pen (there is always going to be berries, just so the best you can to keep it dry and clean), and your goats are overall healthy - fed properly, exercised often, and provided with all necessary vitamins and minerals - you should not need to worm often. By doing fecal tests you can determine if worming is necessary and do only when needed effectively lowering the amount of medicinal wormer you have to use.
Tea Tree Oil is very effective as a topical treatment for lice, mange, and bacterial infections on the skin and feet. At least, that has been my experience. I do not know if it is/isn't safe or effective when taken orally.
I won't launch a full on western medicine versus natural care argument. But I will say this - 200 years ago, well even today in areas of the world who have no access to what we consider western medicine - animals die at astonishing rates. Farmers are lucky to see what we would consider a 50/50 survival rate in kids. The milk is often tainted and makes it's users and drinkers sick. The animals themselves are overrun with parasites and are anemic which of course shortens their life expectancy. It was not a pleasant world for animals being kept in captivity before we began finding ways to treat their problems...
That being said. I firmly believe you should do no harm when caring for your animals. If they don't need it, don't do it. Why overload their bodies with it? And if you can find natural ways to provide your animals with the nutrients they need as well as natural ways to keep them healthy then do so - as long as you don't do it with veld eyes assuming it's the fix all. Sometimes medical wormers are necessary for the well-being of your pets
I use foodgrade DE on all of my animals. Recently we put 40 roosters in the freezer and I was amazed at how clean both inside and out they were. DE does the trick for us. I even put it around the house for ticks and fleas and didn't have any trouble with such this year.