A high Coccidia count does NOT necessarily mean that they are ill. I have had really high cocci counts for my goatlings - and they were fine and are thriving. You would need to have a specific (and probably quite expensive) test done on the FEC to distinguish between the good and the bad cocci.
A high cocci count in young lambs/kids in conjunction with them scouring probably would justifiy a Vecoxan drench (and if they are outside a wormer too).
Vecoxan is expensive but very effective, can be administered to individual animals at the correct dose etc etc. Cocci stay in the soil (excreted from the dams) for well over a year, so can re-infect the lamb crop the following year. However I had a few cases one year, vet said NOT to treat routinely all lambs, but wait for the first one to show signs and then treat all of them - never had a repeat in the lambs since, so never had to treat them.
Getting the odd one for the goat kids (raised inside), but usually all have built up their own level of immunity by 3 months. Also have found it is usually the ones that may have had not enough colostrum are the most likely ones to get ill with it.
However Cocci is often blamed when no other possible cause is readily found... if recently weaned she may just have overeaten on creep feed, too much wet grass or just picked up a bug/virus... (I have found that some of my adult/goatling goats seem to go through a stage of one/two day diarrhoea atm, no other signs of ill health, and a one day fast on hay/water seems to sort them.... I reckon it is a virus.)