I've always used Di-Methox 40% for cocci prevention in my goat kids, but the 40% formula is no longer available. We can still purchase and use Di-Methox 12.5% instead. The recommended schedule is to dose the kid for 5 days every three weeks: day 1 at 1cc per 5 pounds of weight, days 2-5 at 1cc per 10 pounds. (A 20-lb kid would get 4 cc on the first day, 2 cc on the second through fifth days.)
There are other sulfa drugs that can be used instead of Di-Methox. For more information on coccidiosis see this article. Here's one on using Di-Methox from Hoegger Goat Supply, and a chart of other sulfa drugs from Fias Co Farm here. I've read in several places that Co-Rid is not a good choice for goats as it inhibites thiamine production.
Timing is very important when you are giving this as a preventive to coccidiosis. You want to begin when the kid is three weeks old. Don't procrastinate. I "worm on Wednesday" - it's easy for me to remember that way - so I move each kid's dose to the nearest Wednesday rather than their actual 3-week birthday.
The drug is given orally, using a syringe without a needle. I measure out a syringe for each kid before going outside. I hold one kid at a time, open her mouth and squirt it in.
Sulfadimethoxine is really bitter. The kids always spit and sputter and shudder after I give it to them. Once, years ago, a kid shook her head and a drop ended up in my open mouth - now I KNOW why they don't like it! YUCK! ICK! SPIT! GAG! A friend told me this week that she adds maple syrup to the syringe. I did that this week and it is obviously more pleasant for the babies.
Continue dosing your kids on schedule until they are weaned for best protection.