Cocci lives in the soil and when you live in a damp area like here in the south, keeping your litter dry is not going to keep your birds from getting cocci. My birds live outside and do not spend any time during the day inside the coop. They all have large runs in grass. I keep small groups in large areas. I clean the droppings at least every other day in the coop and rake and shovel the outside droppings just about as often. If your soil has cocci spores or organisms and the soild is damp every day from dew on the grass and over 50 inches of rain annually , there is going to be cocci.
In answer to the question regarding vaccinating adult birds, the instructions say to vaccinate between 4 and 10 days old. That is the only mention as to age so I presume it is only effective when administered early on. That does make sense since cocci is something that is usually controlled pretty well with medicated starter. Amprolium used in most feeds is not an antibiotic but rather a substance that inhibits the growth of the organism.
I don't necessarily advocate vaccination for cocci, I happen to have a recurring problem in my runs and after deciding not to feed medicated feed any longer, it works for me. The Vet charges $ 10.00 per stool sample. I keep 7 different groups. If I only had to check each run once a year, It would be $ 70.00. I chose to vaccinate in order to eleminate the worry about cocci and the expense of stool testing not to mention the 35 miles each way getting it to the vet.
