This is a great article on ivermectin use:Hey everyone, I know it has been posted before but for the life of me I cannot find it, nor have the energy to look for it. This is regarding worming. I believe I have saw that ivermectin is safe for chickens right? If so I would love to know how to calculate the dose and how many days egg need to be discarded from it. Right now is the perfect time to worm the flock. The majority are molting so egg production is down to 7 on a good day. I have never officially wormed them before but I have ivermectin on hand now as instead of buying a dose of wormer for the horses we ended up buying a whole bottle this time around.
https://bitchinchickens.com/2019/04/29/ivermectin-for-parasite-control/
For oral use I just used that dosing also (topical application).
You will need an insulin syringe that is a .5ml syringe so that you can dose properly. I gave Red 0.04ml of the ivermectin I have here, it is 10mg/ml strength. She is a good sized bird, I think close to 6lb.
Just check the strength on the bottle some is 5mg/ml and some 10mg/ml.
The key is the smaller sized syringe so you can dose for the 0.04ml for an average size bird, silkies get 0.02ml.