You can check for mites and lice, preferably at night. Many of us worm chickens routinely, though many others don't, or don't use products like Valbazen or Safeguard that will kill them all. If you live in a warm, wet area, worms are that much more likely. Here are a few links you may find useful.
It's a good idea to put a location in your postbit. Just go to your profile and find "location." It can be relevant to a lot of questions.
http://anrcatalog.ucdavis.edu/pdf/8162.pdf
https://www.backyardchickens.com/t/...-i-wait-after-using-wazine/0_20#post_12410869
https://www.backyardchickens.com/t/...solated-rarely-moving-bird/0_20#post_13176194
It's a good idea to put a location in your postbit. Just go to your profile and find "location." It can be relevant to a lot of questions.
http://anrcatalog.ucdavis.edu/pdf/8162.pdf
https://www.backyardchickens.com/t/...-i-wait-after-using-wazine/0_20#post_12410869
https://www.backyardchickens.com/t/...solated-rarely-moving-bird/0_20#post_13176194