I was out in my coop today & I noticed that at least 3 of my 9 hens have projectile watery diarrhea. I have had them for about 7 months, and they were young pullets when I got them. I have never dewormed them, or have had to treat them for anything. They eat layer pellts, seven grain scratch, & occasional table scraps. Otherwise, they appear perfectly normal, eating/acting fine. They do appear to be moulting. Should I just deworm them?? And what sort of wormer should I use?