Rain = deworming again; Must Rotate with valbazen?

[khind]

Of course, the one hen who's actually showing these worms in her stool is the only chicken on Earth who doesn't like bread! I'd forgotten from the last time... I think I'll try making a very small amount of mash with her crumble (which she does like) and the dewormer

 

[khind]

If you are using it monthly, you must never be collecting eggs

Here's just one reference to a veterinarian's statement that most of these deworming medicines don't even get into the egg (scroll to the bottom of page, "About Egg Withdrawal Periods") :
https://the-chicken-chick.com/control-treatment-of-worms-in-chickens/
I think it's one of those issues about which people make their individual decision - take a chance or err on the side of caution.