What is the youngest that one can worm a chicken? I have an americauna which came from the feed store and has had runny poo since I brought her home and a few other of my chickens have it also. I am guessing that worming might help. I do have the same problem I had in the first of the year with tapeworm, so I am going to worm everyone. Some of my girls and 2 roos are sneezing so I am guessing they need it also. I hatched out 2 girls and as of this morning 1 boy. They were born May 6, 8, & 15th. Are they ready to be wormed? The two I brought home from the feed store were born the 22nd of May. Could someone please help me with this question? I would like to get this done ASAP. Thank you in advance, and have a great day.