[Sooz]

One of my chickens has got Northern Fowl Mite.
I identified it by looking on google. (See picture) I got some ivermectin and have treated her and all my other chooks.
I believe there is an egg withdrawal period when using Ivermectin.  As it is an external product, I was wondering why this is so?

[Casey76]

It has an egg withdrawal period because it is not licensed for use in chickens.  Even applied topically you don't know who much will be absorbed by the skin, and you don't know how much will be passed into the egg laying mechanics.