Worming chickens DE Parasites garlic

The 5 myths of worming chickens

Myth 1:  If a bird has worms, you will see it in the droppings.

If you see a worm in a bird’s droppings, it probably already has a long standing infection or a very serious worm burden.  Larger worms such as Ascarids can be visualised and are the most commonly seen worm for most bird owners, but a range of worms exist, and they vary in size with many of them being microscopic and others living in the actual tissue.  Don’t rely on visually checking droppings for worms, most likely you will miss them.  Utilise the Faecal Egg Count Method if you are keen to keep an eye on the challenges your bird may be facing.


Myth 2:  I clean up all the droppings so my birds can’t get worms.

Hygiene plays a huge role in keeping your birds healthy and manure removal is an important part of that.  Using composting floor methods, removal of, or rotationally moving your birds to new areas can help reduce worm burdens.  However, many of the parasitic worms utilize what is called a secondary host or indirect life cycle in which they use a prey species like a worm, insect or other animals in order to complete its life cycle. Some worm eggs can live 1 to 2 years in the soil making them difficult to remove.  So, while hygiene is the best method in preventing some of the more common worms, it can’t be relied on as the only method especially in free-ranging birds.


Thapa S, Thamsborg SM, Wang R, Meyling NV, Dalgaard TS, Petersen HH, Mejer H (2018) Effect of the nematophagous fungus Pochonia chlamydosporia on soil content of ascarid eggs and infection levels in exposed hens. Parasites & Vectors 11, 319–330


worming chickens 

Myth 3:  If my bird has a messy backside I treat for worms.

Diarrhoea is a clinical sign for a number of illnesses including:  coccidiosis, fatty liver, Infectious bronchitis, necrotic enteritis, stress, new feed ingredients as well as a few others.  Treating without knowing what your bird has can lead to resistance towards the medications in many parasites including worms. 


Myth 4:  Garlic or Diatomaceous earth is a great way to de-worm your flock.

Natural products can be good for many issues, but research is still needed to prove that they are effective in some cases.  Garlic has had limited research papers into its effects on parasitic worms.  Recent studies have found that it is not effective at reducing worm burdens.  One paper from 1974 suggests that it could be effective, but the study has some issues with how it was run and the follow-up studies seem to all conclude that garlic has no effect against worms. 

Diatomaceous earth continues to be used in small scale farming and backyard flocks even though research would indicate it has no effect at reducing parasitic worm burdens.  A couple papers have been cited here that show the issue with DE in ruminants.  A few smaller papers can be found as well, but lack good research.  Couple the lack of studies with the potential to cause harm in the form of silicosis in humans as well as animals and this product fails to meet the requirements.


Barnard G, Worku M, Ahmedna M (2009) The effects of Diatomaceous earth on parasite infected goats. Bulletin of the Georgia National Academy of Sciences 3, 129–135.

Fernandez MI, Woodward BW, Stromberg BE (1998) Effect of diatomaceous earth as an anthelmintic treatment on internal parasites and feedlot performance of beef steers. Animal Science 66, 635–641.

  1. Singh, N. Shalini (2000) Studies on the anthelmintic activity of Allium sativum(garlic) oil on common  poultry worms Ascaridia galli and Heterakis gallinae.J. Parasitol. Appl. Anim. Biol., 9 (2000), pp. 47-52




Myth 5:  When I pick a worming agent all that matters is Zero Egg With-hold.

 With-hold times for meat and eggs are used to prevent people from ingesting chemicals used in the food industry.  Eggs are one of the great side-benefits to having chooks.  It is not surprising that we get frustrated when treating a bird for parasites that we have to with-hold eggs from being eaten.  Naturally it is of great benefit to have a worming product that helps us keep all those eggs.  It is important to realise that many chemicals have properties that limit how it can be given.  For example, tablets, liquid or in-feed formulations all exist to serve specific functions namely in the farming sector.  Farmed chickens or other poultry require medications be given via the drinking water and in the feed.  These options aren’t always the best for smaller flocks as water is often not able to be controlled enough to ensure the right dose is given and in-feed options that are not manufactured directly into a pellet do not provide sufficient dosing as well.

It has been seen in practice that sprinkling in-feed wormers such as Flubenol onto pellets or even hand mixing them with oil onto pellets doesn’t achieve the concentration needed to be effective but because the chooks are not checked for worms using a faecal egg count the worm burden is often missed.  This can lead to owners being confused.



Get routine Fecal Egg Counts done.  2 to 3 times a year is best.  Have a look before going into fall, before coming into lay (late winter) and at least a month or 2 after you worm your bird (flock).

Worm with a product that you can ensure proper dosing.  Ensuring that the worms are removed trumps a zero egg with-hold every time.  Make sure if you choose a worming agent that goes in the water that it can be the only source of drinking water for your flock.  This may mean keeping them in a run to restrict their water choices.  Tablet wormers are the best to ensure that the correct dose is given and they are easier to administer for a small flock.  Each circumstance needs its own plan and doing a worm count helps determine which active (wormer) would be appropriate.

Worming prophylactically is not ideal.  But if you are going to do this method then there are some rules to follow.

1)      Rotate the worming chemical you use every year.  Switching the active ingredient helps minimize resistance.

2)      Treat at least twice.  Early Spring and in the Autumn.  Get it done before they start to lay eggs and prior to winter moult as well.  Both of these times help give your birds the best start to the season.  It is important to remember that each time you treat for worms it must be twice to remove juvenile worms or eggs that survive the first treatment.

3)      Hygiene.  Clean the coop regularly.  Elbow grease and hard work as well as building a coop or run that is easy to clean. 


Written by Dr Sam Hurley BSc, BVSc, MAHM

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