Healthy goats are made, not born.
Not our climates or geography, as a rule.
As a result, we fight parasites, like Coccidia, frequently.
They thrive in warm, wet weather, especially.
In adult goats, worms are the battle. In goat kids, it is coccidia, which are not killed by any worming medications whatsoever.
From about 4 weeks of age, especially if the weather is already warm, you need to start treating your goat kids to prevent / control coccidia. Kids born in May, June and after will struggle more than kids born in January, for instance.
If you wait until the coccidia flourish, the intestinal tract of the kid can be damaged permanently, the growth can be stunted and/or your goat kid will die.
If a kid has coccidia controlled properly from a young age, by the time fall comes or by the time the kid is about 6 months old, she will have developed a natural resistance, and you should not have further issues with coccidia as the kid grows into an adult unless the animal becomes very ill.
You cannot get around addressing this parasite. They are all over the environment. You can have a clean environment, you can raise the kids away from the adult herd (adults carry but aren't generally damaged by coccidia if in good condition).
I do not personally recommend Sulmet or Corid.
I use these medications below:
Baycox - I use 1cc pr 5lbs every 10 days (some people use 1cc pr 5lbs every 21 days)
Dimethox 40% - You will use 1cc pr 5lbs on the first day, then 1cc per 10lbs for days 2-5 if preventing every 21 days. If treating 1cc pr 5lbs for 5 days every 21 days.
Below are Coccidia laden kids: