I Want My Free E-Book On Egg Laying Chickens

Chicken Parasites: The Complete Guide Part 2

The Complete Guide To Chicken Parasites Blog Cover

Note: This is the second of a two-part series on chicken parasites. This article will focus on internal parasites and the first part of the series focused on external parasites.

In the first half of this series, we focused on discussing the harm that parasites can cause your chickens. We won’t repeat this information again; however just remember the key takeaway: prevention is far better than cure.

Let’s now turn our attention to internal parasites and look at how you can spot the parasite and more importantly, cure the parasite.

Chicken Parasites

Chicken Parasites: Worms

Worms are by far the most common internal parasite and unfortunately, there are a wide variety of worms.

The good news is that with care and tidy housekeeping you should be able to keep your girls worm-free.

Chickens that roam outside are unfortunately the most likely bird to catch a form of worms.
There are two methods by which a bird can become infected – direct and indirect.

Direct is when the bird forages and eats the parasite’s eggs from infected poop or pasture. Indirectly is when the hen eats another creature (e.g. earthworm, snail, or slug) that is already infected with the parasite

How To Stop Chicken’s Getting Worms.

Prevention is far better than curing and some relatively simple measures can help to keep worms at bay:

  • The parasites’ eggs love wet, warmish, mucky areas, so make sure to keep your runs clean and mud-free.
  • Keep the litter/bedding inside your coop fresh and dry, also make sure to clean up the poop frequently. If you’ve had particularly bad weather and the litter gets damp- discard it as soon as possible.
  • Worm eggs are destroyed by UV light from the sun, so keep the grass in the run short.
  • Sometimes wild birds spread the parasite to your flock- make sure to keep wild birds out of your runs/coops.
  • Quarantine new birds and if the bird looks poorly to start with – don’t bring it home.
  • Give your flock plenty of room, overcrowding leads to many problems, not just parasites.
  • Use apple cider vinegar or crushed garlic gloves in their water once a week- this will help give their gut flora a good balance.

These preventative techniques can be used on any type of worm parasite.

However some types of worms require specific treatment, so let’s take a look at the various types of worms that chickens catch and how to treat them.

Roundworms Most Common Chicken Parasite

Roundworms are the most common type of worm to infect a chicken.

If your chicken has contracted roundworm, symptoms to look for include: a loss of appetite, watery poop, decreased egg-laying, dull comb, wattles and eyes, wanting to be alone, dehydration, and a loss of balance.

Very occasionally in severe cases, a worm can migrate to the hens’ oviduct and a worm will be found inside an egg – a decidedly unsavory experience!

Note: As unappealing as it may look, it is not a health threat to humans.

Younger chickens are more susceptible to worms and will struggle to put weight on them if they have contracted them.

This is why you need to be extra vigilant with young hens, after around 4 months they will develop some resistance to the worms.


There are several treatments that can be used.

Wazine is the most common drug used and is approved for poultry use. It comes in a liquid form and needs to be mixed with your chickens’ water.

Whilst your chickens are given Wazine you can’t eat their eggs– this is known as a withdrawal period. The withdrawal period varies from product to product but it’s typically 7-14 days.

Worms are slowly becoming resistant to some of the more common worming medicines, so I advise you to use wormers sparingly and with caution.

Some people worm their flock every 6 months regardless of whether their chickens have worms- my approach is, if you don’t see a problem, don’t unnecessarily treat your chickens with medicine.

Chicken Parasites: Capillary Wormscapillary worm

This little critter lives in the crop, esophagus, and proventriculus (marked with pink arrows in the image opposite) of the bird.
Its symptoms are very similar to Roundworms: loss of weight, looking tatty, reduction in egg-laying, and food intake.
The treatment of Capillary worms is the same as Roundworms, and you can use Wazine.


Tapeworms require an intermediate host (earthworm, snail, etc) to be able to infect your bird.

They don’t usually cause too many problems, however, they can cause the bird to lose weight and look thin, but they are rarely fatal.

Good coop hygiene and cleanliness is the best way to prevent your chickens from contracting Tapeworms.

Warm Climate Chicken Parasites: Eye Worm

This type of worm is mainly found in warmer climates such as the Southern states of the US.
Again like Tapeworms, it requires an intermediate (i.e. cockroach) to spread.

Symptoms include scratching at the eye, drainage, redness, swelling, and a cloudy discoloration of the eye.

If left untreated it can eventually lead to blindness.
To treat Eye Worm you need to use VetRx.

VetRx comes in a canister which you can then spray over your chickens. After a few cycles of the spray, the worm should be cleaned up.

Respiratory Chicken Parasite: Gape Worms

These nasty little worms reside in the birds’ respiratory system.

If the infestation becomes severe enough, the affected bird will gape its’ mouth to get air – this is known as ‘the gapes’. Other symptoms include: head shaking, hissing when opening its mouth, and stretching its’ neck.

A severely infected bird can die- early signs are lethargy, looking unkempt, and a sudden loss of weight.

If the infection is not very severe then a wormer such as Wazine can be used.
Chicken Parasite Medication
However, in the case of a bad infection you need to consult your veterinarian. They will typically prescribe Fenbendazole- however, be careful as overdosing your bird with this medicine can kill a hen.

Remember: If you are concerned that your birds may have worms, collect a fecal sample from several birds and take it to the vet for testing. The test is relatively quick and cheap.


Protozoa is a single-celled organism- most of which are harmless. There are a few however, that can cause havoc in your flock.

The most common and devastating of these protozoan diseases is coccidiosis.

Coccidiosis is usually more problematic in chicks and growing pullets and is usually the prime suspect in the cause of death between the ages of 3-6 weeks.

Chicks Foraging With Mother Hen
Chicks Foraging With Mother Hen

Chicks who forage with their mothers gradually build up immunity to the disease by being exposed to it.

However, chicks brought in from outside sources are most likely to suffer since they have no immunity to the Coccidia present in their new surroundings.

It is always best to keep new chicks isolated on clean litter with clean water and food dishes for at least 2 months.

If you intend to expose the chicks to your existing flock, you will need to get them vaccinated by your local vet.

If you are raising chickens organically and do not want to use medications, keep your chicks away from the flock until they are at least 2-3 months old, then you can introduce them to your existing flock.

Watch them carefully during this introduction period and if they show any signs of lethargy, looking tatty, bloody diarrhea – isolate them and treat them immediately.

I cannot stress enough the devastation coccidiosis can cause in a henhouse. Although I have never experienced it myself, it is heartbreaking to watch.

As noted many times before prevention is better than cure, so probiotics added to water, a clean henhouse, and frequent health checks can all help to avoid this devastating disease.

Chicken Parasite That Can Affect Humans: Toxoplasmosis

Toxoplasmosis is an infection that is caused by Toxoplasma gondii (T. gondii).

This is one of the few parasites which we’ve written about that can affect both humans and chickens. In fact, it’s estimated that 1/3 of people will be infected by Toxoplasma gondii during their lifetime.

It is spread by rodents, flies, and cockroaches and is found in the poop of infected animals.

Toxoplasmosis is harmless although to prevent you from catching it care should be taken to always wash you’re your hands after being with your birds and make sure to use gloves when you clean out the coop.


Giardiasis is an incredibly rare parasite and it is usually not problematic unless it overruns the immune system.

Chickens normally catch this parasite through pecking at infected poop (dog, cat, etc.) and symptoms include brown watery diarrhea, weight loss, and dehydration.

If you suspect your chickens have Giardiasis, visit your local vet and they will prescribe your chicken’s antibiotics.

Note: Humans can also catch Giardia, so good sanitation and hygiene practices will help to prevent transmission.

Chicken Parasites Final Thoughts

Natural Preventative

Pumpkins are touted as a natural remedy or prevention to worms in poultry and cattle, but as of now, there is little evidence to support this claim.

With that being said, pumpkin seeds have characteristics that may make an otherwise attractive environment for a worm to thrive, less desirable.

It never hurts to give your chickens pumpkins throughout the year, just make sure they haven’t begun fermenting.

You can add pumpkins to your parasite prevention routine because at the least, the pumpkins will provide your flock with a healthy treat.

Cleanliness Is Key

Making sure your chickens are well kept and free from parasites isn’t easy but providing you keep your coop clean and do regular health checks then you are definitely starting off on the right foot.

That completes our look at internal chicken parasites.

If you missed the first part of the series on external parasites you can catch up here.

It should be stressed that most backyard chickens do not suffer from the more uncommon parasites. As always – good sanitation and housekeeping practices will help to limit the exposure of your flock.

All sick birds should be isolated and watched carefully. Take notes of the behavior of the bird, what symptoms has it got? Watery poop? What color? Eating? Drinking?

As gross as it may sound noting all of these things can help you to narrow down the likely suspect disease and will help you treat it more effectively.

Let us know below if you’re going to start keeping a health diary for your chickens!

Want To Share This…

Chicken Parasites

23 thoughts on “Chicken Parasites: The Complete Guide Part 2

  1. We have a chicken who is not using her left side. She also has missing feathers on her chest. Not laying. The vet thought it was a muscle strain and gave antibiotics and a cortisone shot. Not much improvement. Could it be worms?

    1. Hi Melissa,
      I’m sorry to hear this- if you send us an email with photos we will do our best to help,

    1. I would treat the chickens ASAP.
      During the treatment you can’t eat the eggs. You will notice something called a ‘withdrawal period’ written on the medication.
      After this period of time has passed you can continue to eat their eggs.

      1. Before treatment is it safe to eat the eggs or do I have to throw them away? I have a flock of about 70 and we just discovered this morning that there were worms in the eggs

  2. Is there a product that can be used to get rid of worms (specifically tapeworm) where you can still eat the eggs? What about Safeguard?

  3. When I read the wazine instructions it states it is not to be used on egg laying hens, is there any medication to give chickens who have round worms I’m sure I have at least one chicken infected

    1. Another option is Verm-X with no egg withdrawal period
      Wazine can be used, but be aware, Wazine is not approved by the FDA for egg laying hens, only for meat poultry. If you are to use it in the end make sure you throw away any eggs during use and read instructions on the withdrawal timing and follow the calendar!

  4. Thanks for the information I on research currently on intestinal parasites of slaughtered local chickens but finding difficulties to compare my findings using atlas pls can you help me with some important journals and atlas. Thanks

  5. This isn’t complete at all! It’s a vague overview. Doesn’t offer any help to treat tapeworm, capillaria, coccidia, etc.

    1. Hi, after I look up all the things that can go wrong it certainly puts a damper on my spirit. This is my first time I only have 2 chickens but I had no idea of how much can go wrong.
      Just yesterday they started to stay in there bed? Only come down to drink eat!
      I clean a lot and disinfect a lot. It seems to be much more then I had Imagined …
      Any advise is appreciated. Thank you Ingrid

  6. I was unaware that worms could be found in eggs, until I read this website.
    I believe I accidentally ate worm-infested eggs, and wondered if cooking kills the parasites.

  7. Im a new chicken owner, and ive been keeping the juvenile chicks in my basement, and when warm enough outside they have the entire basement until spring but i noticed that one of them has runny black poop. This all started 2 days ago, now today no black poop but its still dark. I have no idea which one of my chickens it is, but a few of my more rowdy chicks were showing symptoms of Coccidiosis ( acting tired, ruffled feathers and not wanting to eat or much…even her fav mashed potatoes. They eat medicated chick starter but i give them ledtovers now and then and she * i think its a she…was not interested at all. Should i just assume that this is Coccidiosis and treat the flock or should i go to the vet

  8. I had a problem with my chickens. lately i
    found they had parasites in their feathers I don’t know what kind of parasites they are but they’re white with red dots on it can I please have help with knowing how to help my how to help my ladies
    Thanks kk Augy

  9. Is there anything that can be transmitted to a person that has 3 chickens and these things that look like bug bites . then these things raise and open with what looks like white stringy stuff that comes out of these things all over my sons arms neck and some on his legs. Is this something that may be causing these things. Is there anything that can be put on these to kill whatever these are?

Leave a Reply

Your email address will not be published. Required fields are marked *