I just acquired a new hen for my little flock of 4. The previous owner had mentioned that she periodically lays shell less eggs. I figured this was just a lack of calcium or being stressed in her past environment. I have her quarantined in a large dog kennel until I'm sure she is healthy. It's been a few days and I have noticed that her rear end is quite messy and damp. She has layed an egg that is very well formed with a strong shell yesterday and her stool looks normal. Could this indicate an underlying problem? I was thinking of adding some tetracycline 250 to her water as a precautionary measure but just read on the package that it shouldn't be used in laying birds... Right now she is getting oyster shells and Stress Aid in her water.