It is basically what you are comfortable with risking. Many people here have rather large flocks, and a great deal of money invested in their flocks, others here have a huge emotional investment, and for them to risk a possible loss that adding new birds, it is important for them to quarantine.
Many people, give them the old eyeball look, and put them together right that night. Many have been lucky and got nothing. Others have infected their original flock and suffered severe losses. Personally, I like having a small flock, I do not have a huge amount of money invested. If I lost all of them to sickness or disease, I would feel bad, but not devastated either emotionally or financially. I would clean things up and try again.
Many people talk about quarantine, but while they keep them separate, they are still very close together, and that is not a real quarantine, very few people have the space or the set up to allow a true quarantine of separate facilities, and a great deal of distance apart.
I think another consideration is where did you get the hens? If it is directly off another person's place where you saw all the hens and their facilities, and they looked and acted healthy, that is a pretty safe bet. If on the other hand, you bought them at a swap or an auction, where they have been highly stressed and exposed to many strange germs, and comes from who knows what kind of place, then I would have considerable more concerns and probably quarantine.
MrsK
