I have 13 young chickens, 10 - 3 week olds, 1 - 8 week old, and 2 - 6 week olds. I was told they were all vaccinated for coccidiosis at the time of purchasing but I just brought home the 2 - 6 week olds yesterday and because I was told they were vaccinated for Marek's and coccidiosis I didn't...