How many grams of dewormer should I give to a 1 kg hen as a preventative?

[santas_little_helper]

My hen is mostly indoors and only occasionally go for a walk in the field. I haven't seen any signs of infection in her stools yet, but can I give her a piperazine dewormer as a precaution?
The prophylaxis manual says to give 40 g per 100 chickens, which is 0.4 g, so should I give as much as in the picture (unfortunately my scale doesn't weigh less than 1 gram)?

 

[BDutch]

Don’t. Its a bad idea to give such medicines as a precaution.

 

[igorsMistress]

You should not worm your flock unless they have worms. Not all wormers work on all worms, you need a fecal float test to find out IF your flock even has worms, and then treat for the specific type.

Our vet doesn’t treat chickens, but she will send a fecal sample off for testing for me. It’s not expensive either.