Ivermectin used to treat worms, but has lost it's effectiveness in recent years because so many used it for mites. SafeGuard or Panacur (fenbendazole) 10% is so much more effective as a wormer, and is available in horse paste or liquid goat wormer--most chickens get 1/2 ml for treatment. Lice...
Click on these 2 links to see some good pictures of lice and mites, their eggs, and how to treat:
http://anrcatalog.ucdavis.edu/pdf/8162.pdf
http://ohioline.osu.edu/vme-fact/0018.html
Here is a good link for vent gleet: http://www.tillysnest.com/2012/12/vent-gleet-prevention-and-treatment.html