Should I Be Worming My Chickens?

Updated 17th, June 2023, first published Thursday, 1st October, 2020

Like most other animals, chickens can suffer from parasitic worms. These are endoparasites that live inside your bird’s body, and are collectively called Helminths by vets.

chickens can suffer from parasitic worms that live inside the body. Endoparasites | Helminths

Do My Chickens Have Worms?

The control and treatment of worms in poultry is an interesting subject. Most of us just want to know the basics about parasitic worms; how do our chickens get them, do they make our chickens sick and how do we treat for them? Many of us have kept chickens for years and have never given much consideration to worming our chooks, whilst others do it routinely. It is really a matter of personal philosophy as to which regime you choose to follow. Our recommendation would be to understand what worms life-cycles are all about, discover what the different types of worms are and how they impact on the way you keep your flock and then make an informed decision from there 😊 Have a go at digesting this article and try putting a few off these good husbandry practices into your weekly chook keeping routine.
Check out our '10 Tips To Keep On Top Of Worms' below - these will go a long way to reducing a potential worm infestation and you will have happier and healthier hens.

Below are a handful of worms that your backyard chickens are most likely to experience.

Roundworms

Gapeworm

Tapeworm

Threadworm

Cecal worms

#1 Roundworms

Ascaridia galli

Roundworms are one of the most common intestinal parasites found in chickens worldwide, especially free range and backyard flocks.
They are round in appearance hence the name. It's a yellowish white, thick worm which can grow up to 115 mm in length. These worms lives freely inside the chicken's small intestine. Roundworms are sexually dimorphic, which means that males and females look different. Males sport a pointed and curved tail where females characteristically have a blunt, straight tail. When a roundworm egg is ingested, it hatches in the small intestine. The resulting larva burrows into the lining of the gut, matures and then re-enters the small intestine to attach itself to the lining of the gut. They reproduce and lay eggs, which are passed out of the chicken in their faeces. These excreted eggs will either infect a new host or reinfect the same host, worsening the parasite load. This cycle is exaggerated when hens are confined (ie, cooped up in the same coop or chicken area) and can result in heavy parasite loads quickly.
While roundworms in chickens infest the gut, they do damage in several ways. Burrowing larva does the most damage because they destroy tissues that the bird needs for the absorption of nutrients. This damage from burrowing can also cause hemorrhaging (bleeding), causing anemia, similar to coccidiosis. Severe infestation of adult worms can block the intestinal tract altogether, causing intestinal impaction.
Some clinical signs of heavy roundworm infestations are vague, such as pale facial features, reduced manure output, lack of appetite, diarrhea, and general lack of thrift. Meat birds will show stunted growth or weight loss, and layer birds will see a reduction in egg output. The more unique signs of a heavy parasite load are the undigested feed in the faeces and the telltale presence of adult roundworms in droppings. If you see worms, you’re looking at a significant parasite load.

Roundworms are species-specific, so there is little chance of cross infection among poultry species or from poultry to pets or humans.

Life cycle image courtesy of http://www.poultrydvm.com/condition/roundworms

Treatment of Roundworm
Flubenol, Aviverm and Pour-On Drench can all be used to treat roundworms in poultry. Diamol (DE) can also be used to treat roundworms - best to add a 2% of overall diet. Treatment is not a one-and-done solution for a roundworm infection. Once chickens are treated, the adult worms will exit the bird along with the faeces. Just because they’re out, doesn’t mean they’re gone, so it’s good practice to clean out your coop after a treatment or move free range chickens to fresh ground and treat again within the prepatent period.
_{Please note if your chickens are severely debilitated we recommend not giving them Levamisole (Aviverm) as this medication will impact their ability to fight infections.}

#3 Gapeworm

Syngamus trachea

Gapeworm are not very common in chickens. These are nasty parasites which attach themselves to the trachea of the chicken, hooking on without moving. A chicken with gapeworm will ‘gape’ which is why they appear to be gasping for air and will stretch their head and neck up to the sky. If a hen does not have any other symptoms of a respiratory problem (ie, runny nose, sneezing, coughing and runny eyes) then she it is possible she could have gapeworm. It is more common for these worms to be picked up through intermediate hosts such as earthworms, slugs, and snails. Larvae are ingested, and travel via the liver and lungs to the windpipe. The bright red y-shaped adult worms (the male and female adults are almost always found attached) are found here, and are between 1-2cm long. Worm eggs are coughed up, swallowed and passed out in the faeces. Gapeworm can become so numerous they actually block the throat of an affected bird, stopping feed, water and eventually air from passing through, causing death. All types of poultry can be affected, including water fowl and game birds, especially pheasants.

The symptoms of Syngamus trachea are obvious from its Latin name (trachea=throat) and its common name, gapeworm. The first sign is a bird that is breathing with its mouth open (gaping), usually with its neck extended upward as it literally gasps for breath, often making a hissing sound. Other symptoms include coughing, fast head-shaking (trying to clear its throat), loss of appetite, loss of condition, weakness, emaciation, grunting due to difficulty breathing. Young birds get weak and deteriorate very quickly if badly affected. Adult birds tend to show fewer obvious signs, and some may show no signs at all.

Gapeworms cannot be transmitted from chickens to humans.

Life cycle image courtesy of http://www.poultrydvm.com/condition/gapeworms

Treatment of Gapeworm
For treating gapeworm, it’s important to use Flubenol or Aviverm as they contain the chemical levamisol which works to kill the adult worms. Ivermectin-based products will not kill adult gapeworms. Treat all your birds, not just the ones showing symptoms.
Ongoing treatment: gapeworm is incredibly hardy, and will remain viable in the soil for more than four years, infecting and reinfecting a flock. They are particularly dangerous to young birds, so rotation of pens is important. Better yet, if you can, quarantine all young birds from adults as a good preventative measure. Rotary hoeing of soil and control of fly, snail and slug populations can also help prevent reinfection.
_{Please note if your chickens are severely debilitated we recommend not giving them Levamisole (Aviverm) as this medication will impact their ability to fight infections.}

#4 Tapeworm

Cestodes

Tapeworm (cestodes) are flat, ribbon-shaped, segmented intestinal worms belonging to the cestode family. They are commonly found in the intestinal tract of backyard or free range chickens worldwide. Unlike roundworm, that live freely in the chicken's intestinal tract, tapeworm anchor themselves into the wall of the bird's small intestine with their hook-like mouthparts. Tapeworms also differ from roundworms in the way their bodies grow, which occurs as increasing segments.
These attach themselves to the lining of the intestine and can get really long and unpleasant. These are less common but can significantly weaken your chickens immune system and leave them susceptible to other health problems.
Most tapeworm won't actually cause physical damage to the intestinal wall, however by taking all the nutrients away from the bird, it is still damaging to their health, resulting in stunted growth/weight loss, nutrition deficiencies, and increased risk of infection or disease. Diarrhoea (sometimes bloody diarrhoea such as with Raillietina tapeworm that use beetles as an intermediate host) weight loss, reduced egg production. One reliable indication is tapeworm segments or worms in droppings; however, tapeworm will not always show up on a worm egg count. Death can occur with substantial infestations.
Tapeworm have an indirect life cycle. They use arthropods and other invertebrates as intermediate hosts (snails, slugs, beetles, grasshoppers, mini-wisps, ants, earthworms, termites, and houseflies). Chickens become infected by eating the intermediate host. Once the host is consumed by the chicken, the tapeworm larvae that was initially contained within its host gets released, into the chicken's gastrointestinal system. From there, the tapeworm larvae attach themselves to the intestinal wall, where they continuously absorb nutrients from food eaten by the chicken, instead of the chicken absorbing it.

Tapeworm cannot be transmitted from chickens to humans.

Life cycle image courtesy of http://www.poultrydvm.com/condition/tapeworms

Treatment of Tapeworm
Flubenol be used to treat tapeworm in poultry.
Worm treatments containing praziquantel are used to kill tapeworm. Two follow up treatments at 3 week intervals are then recommended. Routine three monthly seasonal treatments together with control measures against flies, beetles, slugs, snails, earthworm ingestion is necessary to prevent further infection.

How Do Chickens Get Worms?

Basically, chickens pick up worms from something they eat. Either a chicken eats infected droppings from another bird or the chicken eats an insect carrying worm eggs (earthworm, slug, snail, grasshopper, fly etc). A healthy chicken can cope with a reasonable worm burden. However, should a chicken become unwell or become stressed their immune system finds it increasingly more difficult to cope and the worms have the opportunity to overpopulate. A heavy worm burden can cause, disease, infection and even death.

The life cycle of worms means that getting rid of these pesky beasties can be particularly hard.

Chickens get worms from something they eat which is infected or carrying worm eggs

The Life-Cycle of Worms

Whether you decide to treat confirmed worm cases or worm preventatively, it’s always best to do everything you can to make sure your chickens don’t contract parasites. One of the best things to do is to regularly move their coop and run to a new patch. This will stop serious outbreaks, as it stops the life-cycle of the worms. Worm eggs are expelled in the droppings from infected birds, and survive on the ground for a surprisingly long time before they are picked up by foraging chickens. This is called a direct life-cycle, as the worm doesn’t need a host animal to get to your hens.
Worms that have an indirect life-cycle on the other hand let their eggs first be ingested by for example earthworms, slugs or centipedes, where they lay dormant until the host is eaten by one of your chickens. The larvae hatch inside your hens, and the cycle repeats. To prevent an unbreakable chain of worm infestations, it’s therefore important to regularly move your chickens. This is made easy by portable chicken coops like the Eglu Cube or the Eglu Go UP Raised Chicken Coop. Another useful thing is to keep the grass mowed as the ultraviolet light from the sun can kill off potential worm eggs in your chickens’ droppings. Clean the run every week and scoop up droppings and wet bedding. If one of your chickens is infected it’ll be very difficult to get rid of all worm eggs from the ground, but every little helps!

Regularly move their coop and run to a new patch to disrupt the worm life-cycle

Signs and Symptoms

Symptoms of a heavy worm burden or infestation can include; worms in eggs, abnormal droppings (diarrhoea, foamy-looking etc), weight-loss, anaemic or pale comb and wattles, listlessness, dirty feathers around vent, worms in droppings or throat, gasping, head stretching and shaking, drop in egg production and sudden death. If you are unsure and suspect worms then there is the option of a faecal egg count. Take a dropping sample into your local vet. The sample will be sent away and the results should tell you if there is a worm problem, how serious and what type of worms are present.

Prevention

As with all animals, good animal husbandry will mean less risk of your birds getting worms. This includes regular cleaning out (disinfecting) of coops, replacing a layer of soil every so often if your birds are penned within a run, and rotating free-range areas so birds aren’t foraging in the same place all the time. Making sure enclosed poultry runs are well drained and using fresh bark/mulch/needles in muddy areas may help as its acidic nature discourages parasite and bacterial growth (plus offers the chickens a drier environment to scratch around in!)

Apple cider vinegar is said to be a good way to clean out good & bad bacteria in the gut of poultry

Diamol is natural pest control for worms and coccidiosis in poultry

Natural Worming Remedies

Garlic grated up and added to water can act as a natural preventative. Research shows that it appears to have some success at helping to prevent a worm build-up but will not cure an infestation. Diamol is natural pest control for worms and coccidiosis in poultry, bantams, chooks, chickens and works brilliantly. It is an organic worming treatment that can be added to your chickens feed. Apple cider vinegar is said to be an good way to clean out bacteria (both good and bad!!) in the gut of poultry, but scientifically, that’s all we can confirm. There are many claims about its power as a natural drench, but nothing is proven. Use it sparingly as regular use of it can lead to other health issues.

Diamol

When To Repeat Treatment

If you are worming as part of a prevention routine, most poultry keepers worm at least every 3-6 months, between 2 to 4 times a year. At the very minimum treat in the Spring before the breeding season (when temperature rises and worm eggs become infective) and again at the end of Summer (when egg numbers decline.) However, if you know your chickens have worms or you see worms in droppings then do remember that this kills the worms they are carrying but does nothing about the worm eggs that are on the floor of the run and in the intermediate hosts such as slugs, snails and earthworms. You do need an ongoing treatment plan to kill the worms that develop over the coming weeks as a result of the eggs that get picked up.

The life-cycle of the worm varies between 2 and 8 weeks (see the information below) and is called the “prepatent period” of the worm, so you will need to repeat treatment before these eggs develop into egg laying adult worms producing thousands more eggs. Note that during the prepatent phase of infection, poultry can harbour lots of immature worms that are not laying eggs, so no eggs will be present in the droppings. Treatment should be repeated within this period, 3 weeks after the end of the last treatment (2 weeks for geese) is a good compromise if you don’t know the type of worms that are infecting your birds.

Prepatent period of common poultry worms:

Roundworm: 35 to 56 days faster in young growing birds
Tapeworm: 14 to 22 days.
Gapeworm: 18 to 20 days
Cecal worms: 24 to 30 days.
Hairworms: 20 to 60 days depending on the type of Hairworm

most poultry keepers worm at least every 3 to 6 months, between 2 to 4 times a year

Worm Treatments - Remember to Treat the Whole Flock

Aviverm

Aviverm Poultry Remedy is a quick and easy way to worm your chickens by adding to their water. Estimate the total weight of your birds and add 1 ml per 9kg estimated total bird weight to their water for 1 day replace with fresh water.
Please read the instructions on the bottle carefully as there is an egg withholding period of 7 days after treatment.

Aviverm

Follow good husbandry techniques combined with regular worming as per the manufacturer’s instructions

10 Tips To Keep On Top Of Worms

Prevention is always easier than cure so follow good husbandry techniques and combined with regular worming (according to the manufacturer’s instructions), you shouldn’t see any problems.

Feed chickens properly. Stick to a complete nutritionally balanced diet like Westons Peak Layer Pellets. Keep treats to a minimum.
Do not throw feed and treats on the ground for them to become contaminated by poultry droppings.
Keep feeders and drinkers clean.
Do not overcrowd your chickens. Give them us much space as you can.
Practice good coop hygiene and maintenance with regular cleaning. Keep litter in poultry houses fresh and always ensure it is dry.
Ensure your flock has access to to a sunny, well drained run. Worm eggs are destroyed by Ultraviolet Light (UV) from the sun.
Worm eggs thrive in wet, warm, muddy areas. Remove muddy areas such as those found by pop-holes by creating hard standing or free draining gravel.
Worm eggs cannot develop when it is very dry, when the temperature is below 10˚C or above 35˚C. Worm chickens as the temperature rises in spring.
Rotate pasture/pens/runs periodically. If you have a movable coop move daily onto fresh grass. Replace the bark or sand in your run annually or twice a year. Keep grass short and rotate pasture in the summer if you can to help prevent a build up of worm eggs.
Keep the harmony in your flock to reduce any stress.