Ditto what Toddrick said...just feed scrambled or cooked, never raw, as in crack open a shell and let them eat it as that could encourage egg eating.
I have a few birds that sneeze occasionally too. I think it is dust related...which is why I suspicion your unused dog run.
But then I've had illnesses begin with just sneezing, and in a week somebody else is sneezing then gets sicker while the first bird just sneezes and gets a mild case. I had Infectious Bronchitis go through the flock that way, from a gently nicking bird I brought in, isolated (but not enough down wind), who only gently sneezed then stopped while within days I had a major breakout after another gave a gentle sneeze.
It is always good to err on the side of caution with a mature bird that you are bringing into the flock, especially if you've got AI in the area. (We just had a big scare out here in Oregon too).