Just got two new pullets (hatched late July or early August, I believe). I've had them 5 days and they are in quarantine from my other two girls. I have heard a few sneezes out of at least one pullet, but I don't think there is any nasal discharge and they seem to be eating and drinking normally, but I have definitely heard a few sneezes. What else should I look out for and how will I know if I need to be concerned? I plan to keep them quarantined from my big girls for another 10 days. Is that long enough? Is there anything specific I should do at this point? Would electolytes/vitamins in the water help?
Most people quarantine for at least 30 days. Others will even place a chicken they don't mind losing in with the new birds for up to a month or so to see if that bird gets sick. A lot of birds can be non-symptomatic carriers of things like MG, infectious bronchitis (IB,) and other things such as Mareks. Most respiratory diseases make cause symptoms within a few days while Mareks can take 3 or more weeks. Some people add birds to their flocks without ever having a problem, while some bring home diseases with their first chickens. Just occasional sneezing can be from dusty conditions or feed, but continuing to sneeze may be IB. Here is a good list of common diseases that has symptoms and treatments, along with a second one concerning biosecurity and quarantine: