I've never given them anything at all, but having done a lot of research once Olivia got sick, I'm now wondering if I should. And if so, what? I have 3 chickens, w/ no intention of getting more. Olivia had a completely clean fecal at the avian vet's. Do I need to do anything as far as preventative worming? I prefer not to give them toxic substances without good reasons . . . . Would it be better to just take a fecal sample in every few months?
If the sample was neg, I would not give them anything. As far as I know, wormers oly kill parasites that are present. Routine worming prevents a large build-up of worms.
I personally would not treat unless there was a problem. The fewer chemicals, the better. Clean fecal = good job! If you like, it is certainly not a bad idea to have them tested a couple of times a year.
You can add food grade DE to their feed and you'll have preventative maintenance. Check here...http://www.shadowridgedonkeys.com/perma_food_grade.htm I will be adding it to their feed as well as in the bedding in the coop.