My 10 week old guineas are on dirt floors in the pen and coop with heavy straw. Should I be worming them? If so, with what? I hear horror stories about people worming chickens (with Wazine) and their flocks of youngsters keeling over dead. I've put some diatomaceous earth scratched into the dirt down - - is that enough? Also, will play sand in a "bath box" suffice as grit? I should already know these things but I don't. Thanks!