Flubenvet is the only licensed in feed wormer for chickens. It is very effective at killing worms and their eggs. Worms can cause a huge amount of damage to chickens and cause many health problems. As a rule of thumb, if I have a sick bird, the first thing I consider is whether or not she was wormed recently before exploring other avenues.

direct life cycle of wormsWorms lay thousands of eggs in a day that are not always visible in droppings. Eggs then either get picked up by birds scratching around the floor, eating from the ground or in their litter when housed (i.e. picked up directly) or are eaten by earthworms or other ‘hosts’ and passed on to our birds when they themselves get eaten (i.e. indirectly picked up).

These two routes of infection are called the ‘Direct Life-cycle’ and the ‘Indirect Life-cycle’ and can be understood better from the diagrams show that are kindly supplied by Elanco (formerly Janssen Animal Health) where two examples of direct infection and one indirect are shown.

indirect life cycle of wormsWorm eggs are destroyed by heat, drought, a hard frost and UV from direct sunlight. For this last reason, after worming in the Spring, I keep grass short in runs over the hotter summer months where my hens graze so that worm eggs can be destroyed. Over the colder winter months or below 10 degrees Centigrade. Worm eggs cannot mature and therefore cannot become infectious so I try to worm in the Autumn as the temperature starts to drop.

Flubenvet is very effective and after the recommended 7 day treatment, chickens are free of worms and eggs. One thing to remember is that the thousands of eggs deposited via droppings (or coughed up in the case of Gape Worm) are still present in the environment so if the worm infestation is bad, you will need to repeat treatment with Flubenvet after 3 weeks to break the cycle before the newly acquired worms (picked up from the eggs) have a chance to mature and lay eggs themselves.

The withdrawal period stated on the tub is nil for eggs from laying hens. This means that you can continue to eat eggs whilst your chickens are being wormed with Flubenvet. I’m sure you won’t be eating your hens but they must not be slaughtered for human consumption during treatment. Treated birds may be slaughtered only after 7 days from the last treatment.

Where to buy Flubenvet

flubenvet wormer

Click Image to Search for Flubenvet on Amazon

If you have a small flock, there is a Flubenvet 1% 60g pack sufficient to treat around 20 large chickens. This comes with a handy little measuring scoop so that you can get the quantity right. One 6 g scoop treats 2 kg of food for chickens. This is the simplest way to worm and if you mix it as I suggest above with a little oil, you can be sure your chooks are getting the required amount.

If you have 50 or more chickens, I would suggest you buy the Flubenvet 2.5% 240g gamekeeper pack which lasts longer. This is harder to find as it is more of a commercial quantity. In order to weigh out the small amount required, you will need some accurate electronic scales that can measure to 0.1 grammes.

How I mix Flubenvet.

mixing flubenvet with layers pellets

Adding the Flubenvet ‘paste’ to the layers pellets before mixing well

Flubenvet comes as a powder that must be mixed with your chickens feed. In order to get this to stick to my layers pellets, I mix it in a small tub with a little Olive or Cod Liver Oil. The ‘Flubenvet paste’ that this makes can then be poured over the right amount of (weighed) pellets in a bucket  and mixed well. It sticks to the pellets and won’t fall to the bottom of the bucket like I suspect some of the powder would without the oil.

Remember to wear disposable gloves for safety (yes I know we forgot in the photos!) and follow the ‘operator warnings’ given by the manufacturers below at the end of this page. Remember to dispose of empty containers in the domestic refuse. Used containers should not be recycled.

Pre-Mixed Flubenvet

It is getting harder to find Flubenvet 1% at a reasonable price – (£24 – £25 at the time of writing this) so one option is to buy a bag of pre-mixed layers pellets with Flubenvet already added. This also takes the pain out of having to mix it with the pellets evenly!

One ‘complaint’ people have is that a 20Kg bag is too much for their chickens for a 7 day treatment of Flubenvet, however you should keep in mind that layers feed lasts for around 6 months before starting to spoil so you can use it for 2 or 3 worming treatments.

You can Buy Layers Pellets Pre-mixed with Flubenvet on Amazon HERE

How often do I worm my Chickens

As you will see from my routine list of jobs and from what I said above, I use Flubenvet twice per year as a preventative measure but I also worm new birds that we add to our flock and if I become suspicious of worms / ill thrift.

I rotate the runs my birds use so there is no build up of worms. I would suggest you worm every 3 months if your birds are on the same ground continuously.

In between times, I will use Verm-X and Apple Cider Vinegar monthly to help keep worm numbers down as well as keeping the grass short in the summer months to allow UV from the sun to kill worm eggs.

An interesting fact: According to Janssen Animal Health, Flubenvet has been used to treat chickens and other poultry in 56 countries for more than 15 years.

You can read more about worms on my worming chickens page

Operator warnings

The following operator warnings are given by the makers of flubenvet.

  • The product is a powder and mixing may generate dust.
  • Prepare the product in a well ventilated place.
  • Do not breath dust.
  • If accidental inhalation of dust occurs, move to an outdoor area with fresh air.
  • To avoid accidental inhalation wear a disposable dust mask (that conforms to European Standard EN149)
  • Accidental ingestion by humans should be avoided.
  • Avoid direct skin contact. Wear impervious gloves when mixing and handling the product.
  • Wash affected parts if skin contact occurs.
  • If accidental eye contact occurs, immediately rinse thoroughly with water.


232 Responses to Flubenvet

  1. Emma says:

    Hi, is it okay to feed flubenvet mixed into corn rather than layers pellets? One of my hens isn’t eating pellets at the moment. She will only eat sweetcorn and scratch. How can I treat her with the flubenvet if she’s off the layers pellets?! She also has bright green/ blue in her poops (which are mostly urates as she is drinking but hardly eating a thing) i think something else might be wrong with her but I want to worm first as I have had feacal sample tests and have had confirmed capillia eggs so need to treat all six of my girls.

    • Keeping Chickens says:

      If she isn’t eating then it sounds as if she is seriously ill and is unlikely to last long. Technically you should take her to your vet and he might use a liquid wormer but some will use a small half grape or other treat a chicken will eat and put a tiny amount of Flubenvet stuck to this to at least get some into her.

      If she will eat mixed corn, I would mix it with that though since the amount can be measured and mixed accurately. With the grape method, it’s complete guesswork.

  2. debbir says:

    Is it ok to treat an 8 week old miniature silkie chick with flubevent for gapeworm?

  3. Charles says:

    Thanks for the very detailed guidance. We have 4 warrens purchased a couple of months ago at POL. They laid well for a few weeks before stopping overnight with a worm attack. I’ve administered flubenvet for 7 days which has made them a lot better, but they’re not laying. Should I be concerned or just patient? Thanks for your help.

    • Keeping Chickens says:

      Most chickens have stopped laying now – the daylight hours are too short.

      Their peak production time is the spring so as we get to the end of January / into February, you should see eggs.

  4. Alison says:

    we have treated our 6 chickens with flubenvet 1% layers pellets. We have treat them for two weeks. They have eaten the pellets and nothing else. Can you over treat? Can you continue to mix these layers pellets with the ordinary pellets.

    • Keeping Chickens says:

      I believe for a zero egg withdrawal period you should only treat for 7 days. Outside of this is ‘off label’ and untested and should only be done following the advice of a vet.

  5. Sarah says:

    Hi my hen’s comb and wattle looks pale and shrivelled, she’s not laying and I’ve seen blood / mucus in her poo. She is eating, drinking and acting fine. I had red mites recently so thought she might be anaemic so I’ve treated her & the coop for red mites and there’s no sign of them now, I’ve put cider vinegar in her water and I’ve just bought the flubenvet so hoping that would work. The other two hens she lives with seem fine. Do you think it sounds as though she has worms? Thank you

    • Keeping Chickens says:

      I would wait and see if the Flubenvet helps – if not, it’s not worms and you’d need to ask a vet. Sometimes blood in the poo is just part of the intestines coming lose but this is very occasional.

  6. neil says:

    I’ve just found what looks like worms in the bottom of the coop. They was only in one dropping and I’ve not seen anymore in any other dropping. They didn’t wriggle, just looked dead. Do I need to worm my 3 chickens?

  7. Peter says:

    We have just got our first 3 brown hens and have come across your wonderfully informative website. The hens came from the flock ranging in the field belonging to our local feed supplier and are just over 1 year old. It is unlikely that they would have had any innoculations, so I was wondering if they should be taken to the vet to have jabs or whether using Flubenvet would be better. All 3 look in good health and settled in very quickly. One is producing 1 egg every other day so far – golf balls have been deployed! Many thanks.

    • Keeping Chickens says:

      Vaccinations need to be done as chicks so it’s too late now – but don’t worry, most chickens aren’t vaccinated. Flubenvet is a wormer (in the UK) and should be used periodically to control worms. Other countries use different wormers so you would need to enquire locally and find out what is being used.

  8. Val says:

    One of my pekins is occasionally stretching her neck slightly and opening and closing her beak – maybe gapeworm? She’s not making any gasping sounds and seems perfectly healthy. I haven’t wormed them yet – they are in a mainly covered run and are about 10 or 11 months old – so I have decided to give them Marriages layer pellets premixed with Flubenvet and then repeat within the prepatent period for gapeworm which is 18-20 days I think. I use Nettex sanitising powder in the coop and run so hopefully that should kill any worm eggs too. Does that all sound sensible?

    2 weeks ago I put 3 silkies in with the pekins – they are apparently 20 weeks old though I suspect one is a younger as she is smaller and her feathers seem less mature than the others. I was told they had been wormed though I don’t know when that was. Will it be ok for them to have the Flubenvet layer pellets at the same times as the pekins even if they were wormed fairly recently? I don’t want to overdo it if 3 lots with maybe only 2/3 weeks between each treatment is too much for them! What do you think please? And would some live yoghurt for a few days afterwards be a good idea?

    Loving keeping chickens but only got my first girls last April and there’s a lot to learn!

    Thanks for this great website.

    • Keeping Chickens says:

      Yes, it sounds like a plan. Many problems go away after worming, it’s the first thing to check. Yes, a repeat treatment for the Silkies is unlikely to cause them any problems.

  9. mandy says:

    My chicken has become poorly whilst being wormed ?

    • Keeping Chickens says:

      It could be coincidence but it is possible that she was carrying a heavy worm burden. When the worms are killed, they release toxins which can kill a chicken.

  10. Rosie says:

    Thank you so much for your helpful article. I feel I have a much clearer understanding of worms and how best care to care for my hen. :)

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