Chicken Wormers: All You Need To Know

Chicken Wormers All You Need To Know Blog Cover

Chickens, like most mammals and birds, are prone to worms.

Some of these little beasties can cause all sorts of problems for your chickens.

We are going to give you a ‘worm primer’; what they are, what they do and how to treat them, before explaining how to prevent occurring in the first place.

There are a few different types of worm so we will take each one individually and run through symptoms, causes and cures, including chicken wormers.

Backyard Chickens and Worms 101

Before we start, please do yourself and the hens a favor. Gather some poop from your chickens and take it to your veterinarian.

They will be able to perform a smear slide or float test.

This test alone will tell you quite accurately whether or not you need to worm your chickens. It is quick and relatively inexpensive and may save you the cost of buying un-needed worming medicine.

Overuse of worming medication causes the worm to eventually become resistant to the worming medications, vets are already seeing this.

Direct and Indirect Lifecycle of the Worm

Chicken WormersParasitic worms can be divided into direct and indirect life cycles. What does that mean?

A worm that has a direct lifecycle is one that lives its’ entire cycle within a chicken. The eggs are shed in chicken poop and when another bird pecks at it, that bird becomes infected too.

An indirect lifecycle involves another species (usually slugs, earthworms or snails). The parasite is ingested when the chicken eats the earthworm. Some parasites have even more convoluted lifecycles, but I won’t bore you to death here!

Typical Medication for Chicken Worms

Vetrx Poultry Aid Vetrx Poultry Aid

  • A natural and effective relief from worms.
  • Either apply directly to individual chicken or place into their water to treat at a flock level.
  • Entirely natural remedy that can be administered in seconds.

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Durvet Ivermectin Pour On De-wormer Durvet Ivermectin Pour On De-wormer

  • Simple, easy to use, pour on chicken wormer.
  • Just pour the solution on your chicken’s neck to eliminate worms.
  • You can use this product on individual hens or on your entire flock.

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Fleming Wazine Chicken De-wormer Fleming Wazine Chicken De-wormer

  • Simple and easy to use for flock wide prevention and treatment.
  • Just mix solution with either feed, or water, to treat your hens.
  • Use caution with laying hens as it normally has lifetime withdrawal.
  • Can be effective in as little as 24 hours.

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Types of Worms that are Harmful to Chickens

Capillary Worms

These are small thread like worms, so small you cannot see them with the naked eye – a magnifying lens will show them. There are several types of capillary worm that will live in the chickens’ crop, intestines and ceca of the bird. In severe infestations they can move up into the throat and mouth of the bird.

Capillary worms can be ingested by eating earthworms and slugs or by rooting through well built up litter.


The bird will become weak and anemic with a pale comb. It will look poorly, have decreased appetite, appear emaciated and may sometimes have diarrhea. In severe infestations the bird may die.


There are several drug treatments for these worms. You should consult your veterinarian as some of these medications have not been approved for use in poultry.

Of course, once you treat the birds you must not eat the eggs or meat for the specified withdrawal period.

Why? Two reasons spring to mind:

  1. Firstly, although slight there is a possibility of allergic reaction to the medication by a human.
  2. Secondly, repeated exposure to low dose medications can lead to microbe resistance.

Gape Worms

Gape worms (Syngamus trachea) are nasty things. They inhabit the windpipe of birds and feed on the blood they obtain from the micro blood vessels.

In severe infections the worms can cause a partial obstruction of the windpipe leading to the bird gasping or gasping for air.

They look like a Y shape; this in fact is the male and female locked together in almost permanent copulation.

The eggs are coughed up, swallowed and excreted in the poop where the next chicken will pick it up.


The affected birds will look shabby and tatty. They may cough and frequently gasp for air; you’ll also notice a decreased food intake.

Worms in Chicken

Tape Worms

Tapeworms are flat, segmented ribbon-like worms that attach themselves to the intestinal lining. The shed segments are fairly easy to see in the poop – they are flat, rectangular and white. Tapeworms are fairly uncommon in chickens.


They suck nutrition out of the host leading to weight loss, emaciation, depression and a generally unkempt appearance.

In growing juveniles a lack of proper nutrition can lead to stunting of growth.

When the tapeworm sheds some of its segments, each will contain an egg which can be eaten by beetles, slugs, snails etc.

In due turn the infected insect is eaten by a chicken and so the indirect cycle continues.

Round Worms

Round worms have a direct lifecycle – that is they live their lives in the chicken. An infected hen will shed the eggs in her poop; another chicken will peck at it and become infected themselves.

They are the most common of the worm infestations in chickens. The worms can be seen by the naked eye as they are quite long – they can grow up to 6 inches (12 cm) in some cases. They live in the small intestine of the chicken.


These worms can cause pale comb and wattles, decreased appetite, shabby appearance, diarrhea, wasting and stunted growth. In severe overloads they can cause an intestinal blockage killing the bird.

Eye Worms

Manson’s eye worm used to be a solely tropical disease, but in recent years has moved into the warmer areas of the temperate zones – such as the southern States of the US.

As its name implies, the worm lives in the eye of the affected bird. Infection is usually caused by infected cockroaches although infected feed, bedding or poop from an infected bird can spread the disease.


A cheesy type discharge from the eye, it can cause the eyelids to stick together. Your hen will scratch at the eye, conjunctivitis, decreased appetite, droopy head and eventual blindness if untreated.

The eye worm is treated with special medication that is obtainable from your veterinarian.

Cecal Worms

Cecal Worms in chickens are very common and generally don’t cause too much of a problem.

They live in the ceca of the chicken and have a direct lifecycle.


An overload will cause the bird to look depressed and have a ratty appearance.

The reason we mention it today is that the cecal worm is responsible for Black head in turkeys – ideally you won’t raise turkeys and chickens together.

Control and Prevention of Worms

Obviously, when it comes to your flocks’ health, prevention is the best way to go. In this section we are going to give you some helpful hints and suggestions to try and keep your hens in great condition using natural products.

First and foremost is good husbandry.  Keeping your coops and chicken areas clean and not letting the chicken waste pile up is a great start. The use of Diatomaceous Earth can help to keep down the numbers of parasites in the coop – especially lice and mites.

If possible, you should rotate your hens through different areas to prevent a soil build-up of parasites.

Many parasites (not just worms), love warm, damp places – they thrive in those conditions. Try to keep the runs and surrounding areas where the chickens go as dry as possible. Fill in those mud puddles with pebbles, sand and dirt to discourage standing water.

Keep the grassy areas that your chickens use short. The UV rays from the sun will destroy many eggs and pests.

Make sure your birds have clean, fresh water available at all times. Adding Apple Cider Vinegar to the water discourages the growth of algae and mosquitoes. The ratio is 1 tablespoon of ACV to 1 gallon of water – you only need to do this 2-3 times a week.

You can also add crushed or minced garlic to the water, 2-3 cloves should be sufficient.

Natural wormers such as Verm-X can be used safely with your flock. It’s a herbal preparation that’s been around for a while now. As always there is controversy over its’ efficacy with some folks swearing by it and others saying it’s useless.

Try to keep feed, treats and other food off the floor to avoid contamination.

Also, you can also try Vet Rx as a general tonic for your ladies – another herbal preparation that’s been around longer than I have!

Vetrx Pour On Yes 5 star rating
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Ivermectin Pour On No 4 star rating
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Corid Pour On No 4 star rating
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We hope this has helped you to get to grips with worms!  As always, do your homework, get a fecal float test done and proceed with the treatment of your choice.

You should be aware that a few of the wormers we mentioned are not approved for use in poultry. They require the authorization of a veterinarian for use in poultry.

Unless your birds have a heavy worm load and are exhibiting symptoms of illness, you do not have to worm your chickens. Healthy adult chickens rarely suffer from a worm overload. They do have worms – that’s a fact of life, but in a healthy bird, the parasite and the host live together in a sort of tolerant relationship.

I have hens that are now 8-9 years old; they have never been wormed as they have not exhibited any symptoms or problems.

Other folks worm their flock regularly using a variety of wormers to prevent the worms becoming resistant to one or more of the medications.

Use your best judgment, observe your hens. In small flocks it’s usually easy to see those that aren’t feeling perky, treat accordingly.

Let us know your thoughts on worming chickens in the comments section below…

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  1. Brenda Nepute says

    I have three hens and they are free range and are in at night. My question for you, one of my hens has started going off behind a certain bush at night instead of going to her pen. The other two go to the pen as soon as it starts getting dark. Seems off to me. I have to pick her up and take her to the pen. During the day she is out with the other two like normal. Can you help me to understand why she has suddenly started do that? I love your articles as they are very informative.

    • The Happy Chicken Coop says

      Hi Brenda,

      This can be a sign that there are mites in/on the roost. Have you checked for any parasites?


  2. Chelsea Jones says

    Hi there!!
    So of the 7 I have, one that used to be a decent egg producer is now not producing. She look shabby for about a month. She acts the same and hasn’t changed personality wise. The only thing is she is pale in the face. It’s been like this for a few months now. All the others are crazy and the same but all have the healthy red appearance. Any thoughts?

      • Dawnita May says

        wow…mouNting? Hmm…I thought that was a rooster thing. Seriously…it is MOULTING…and it is normal…but should not last more than a few weeks.

  3. Mary says

    2 of my 6 chickens are having reoccurring diarrhea. Last week I finished treatment for coccidiosis, as I thought this was the reason for the diarrhea. While it started to clear up during treatment, it came back as soon as I stopped (treatment period was over). The symptoms are, white water-like droppings that run down the bottom from the vent. Feathers stuck together, and missing due to constantly being wet. No change in appetite or activity. These are 3 year old hens, so egg production is not reliable. Any suggestions?

  4. LEIGH ANNE says


  5. Roberta Easter says

    Why would someone use wazin on chickens if it has a lifetime withdrawal? I just ordered it now I wont be able to use it because I eat the eggs.

    • HappyChicken says

      I would check the specific withdrawal time for the Wazine you end up buying. Some people continue to eat the eggs while using it but I would make sure the company says that is okay or the label tells you your specific withdrawal time and what is safe.


    • Stephanie Brown says

      I believe the egg withdrawal time for Maxine is 28 days. I’ve used it and eaten the eggs after the 28 days

  6. Homerenovates says

    Please read the article carefully. It is specific about saying that you need to observe a withdrawal period for certain poultry wormers.

  7. Deborah Ruppel says

    I treated my hen for gapeworm and was wondering if there was anything I could do to help her. She seems to be trying to expel the worms now. I’m using dropper to keep her hydrated.

  8. Robert Vandermoor says

    Not saying this will work for chickens but I know coyotes regularly ingest slugs when they have worms. The result is the stickiness of the slug slime binds with the worms and eggs and is excreted. I have seen this many times in fresh coyotes scat a ball of worms.

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