How do you get the chicken to take the Ivermectin? Do you need to get a smaller syringe? It seems that it would be hard to get it into their little beaks. sorry for the ignorance but I just started my flock in April so I am new to this. I have not given them any meds at this point. Could you use DE in place of sevin as a preventative?
I've read that many worms are resistant to Ivermectin, so I use Fenbedazol (Safeguard brand). It's about 10x the price, so that could be rumor started by Safeguard to sell more of their product . . .
I give oral meds with a syringe with no needle attached. Hold the bird firmly and force their beak open. Be careful not to squirt into their trachea (windpipe), so I squirt slowly and to the side, the goal being to drip it into their mouth, but not at the tip of their beak, where they could fling it out. This works best with 2 people, unless you have great coordination and patience.
For deworming, I have started adding the meds to a pan of wetted feed. They love to eat wet feed and will gobble that down quickly and completely, compared to adding it to the water, which seems like a lot is wasted. The only issue I see with this is that some birds may not get as much as others. Multiple pans so they can all eat at once would make that less likely. I did that last weekend and it was a breeze to worm all the non-layers. I hate tossing eggs, so I haven't wormed our laying flock for a while.
I've never used DE. I don't think it's as benign as some say. It could work in nest boxes and on roosts, but don't breathe it, or allow the birds to breathe it. I also think it's only effective when dry and the bugs walk over it, like boric acid for roaches. When I was young, we used a nasty pesticide to paint the roosts, so the lice would die when traveling to new places at night. I haven't seen "roost paint" recently, so I imagine it was banned. Sevin dust is still around and that was the staple for lice control back then. It's interesting that no resistance has happened, as it still seems to be effective, and (relatively) safe.