it could mean several things
(1, from
WikiAnswers - Why does your chicken sneeze Chickens and Roosters question: Why does your chicken sneeze? Do you mean one particular chicken? Does the chicken sneeze only sometimes, then seem fine ...
wiki.answers.com/Q/Why_does_your_chicken_sneeze - 49k - Cached - Similar pages
Why does your chicken sneeze?
In: Chickens and Roosters
Chickens have noses that are just little holes next to their top beak. When they peck at the ground or eat messy things, they will wipe their nose on the grass or their body to clean their nose. Sometimes, I think, it helps to sneeze.
Sneezing is often just a way for the chicken to clear dust and debris from its nasal cavities. Careful observation of the birds general health is needed to determine if something more is going on. Check for mucus around the mouth eyes and nostrils. See if the chicken is active among the flock and going about its daily routines.
If the bird is quiet and inactive during the day then you can assume it is in fact sick. Partially closed and dull eyes are another sign the bird feels unwell. A water soluble tonic called Polytonine A added to the water will help perk up the flock and is available under several brand names from local feed and grain suppliers. Watch for loose stools and blood in the feces, these are signs of more serious problems.
(2 from
Your Bird's Health by The Easy Chicken for beginners ... Brought to you by The Easy Chicken Poultry and Supply. ... It can cause respiratory problems for them, and sneezing/allergy fits for you. ...
shilala.homestead.com/tips.html - 20k - Cached - Similar pages
Cleaning
This is probably the easiest way to avoid sick birds. Over-cleaning is not necessary. The birds need to have access to droppings to maintain natural "gut flora". I know it sounds awful, but it's absolutely necessary for their health.
Excessive dust in their coop. It can cause respiratory problems for them, and sneezing/allergy fits for you. I hose the coops down entirely on a regular basis (3 months or so) to keep them as dust-free as possible.
if you goto
http://www.google.com
put in
chickens sneezing and read there are a lot to learn there