Sick brown hen, is she infectious and could others get the same..help please

I am looking for some help as my vet is clueless as chickens are not his bag.

My sick chicken Dale Is a brown hen who is 3 to 3.5 years old, I've had her from when she was between 6 months to a year she has always been a sneezer when scratching but she did her first molt about this time last year and she has never been right since. She has rarely laid since her molt and about 3 months ago she laid a lash egg,,, didn't know what it was at the time, then about two weeks ago she laid a solid lash which when broken was just cold scrambled egg. Then three days ago she laid an egg, so I thought Things were better, then today one of the other chickens was running around with a hard boiled yolk, I think from Dale. I bathed her as her rear end was a bit poopy but she has a clean vent. As she dried off she laid what looked like intestine?? Pinkish in a thin white liquid. Now a couple of others have started the odd sneeze. Does anyone know what is going on? Or what I should do? I'm very upset as I have 7 of all different varieties and am worried about them all.

Thanks

Franjfl

 

Thanks I think the poop from the pertinitis looks most like Dales