When to deworm? Prophylactic or as needed?

[bwebb7]

I have a flock of 20 hens hatched May 16th. I treated them with Piperazine when they were 6 weeks old. (I always wormed puppies at regular intervals) I haven't started to get eggs yet-though soon I'm sure.
What I want to know is should I go ahead and Ivermectin them before they start to lay or just treat as needed?
I hate to think they are walking around with parasites. I would think they could decline quickly?

 

[Dustoff79]

You might try adding food grade DE to the feed, it will help with internal parasites and reduce flies in their poop. It is non-toxic, does not affect the chicken, it's meat or eggs are completely edible. I use it in my horses, dog, and cat and will when my chicks arrive.