How often should  I de-worm by chickens ?- Answer by Dr Phil a  Chicken Vet

There are several kinds of worms that cause disease in backyard Chooks. The main ones are  are tape worms, round worms, and hair worms. the worms have incredibly complex life cycles.

Chickens can be infected both from eating food infected with droppings containing worm eggs worms and insects and snails containing worm larva.

Poultry vet - Controlling worms in chickens

1. preventing food being contaminated by droppings or poo
2. treating chickens for worms if needed
3. Good hygiene around the birds
4. Feeding the birds off the ground
5. Giving table scraps to birds on a tray or paper and never onto the dirt.
6. Keeping the area as dry as possible. 

the realive sizes of the worms - one can really only see roundworma and tape worm with the naked eye.

Credit: Illustration by Barbara Frake

What should i de-worm my chickens with ? - Answer by Dr the Chicken Vet  

1. use a product that is effective
2. use a product that has no withholding IE you can eat every single precious egg without worrying of medications in the eggs
3. WE recommend - Chook Levami - Out home brand for Egg laying birds
4. Ideally know what worms you are dealing with as some can be harder to treat especially capillaria or hair worm
5. POULTRY VET TOP TIP : Look for products containing Levamisole only !