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.


260 Responses to Flubenvet

  1. izzy says:

    Can I mix Flubenvet with cooked corn, as they love it and I’d be sure they ate it then, as they are spoilt chicks and they prefer to eat there cooked corn first in morning.

    • Keeping Chickens says:

      You could – but I would take a step back and sort out their feeding (read my page on this).

      The problem is, Flubenvet has been tested and is licensed to use in their feed. So a chicken of a certain weight will eat a certain amount of feed and therefore get a certain dose of Flubenvet for their weight. If you start giving it with other feeds (a popular one I read about is people using half a grape to stick some Flubenvet to which ‘makes sure’ each hen gets some) then you are taking pot luck at the dose and giving it all in one go.

      What if they stuff themselves with cooked corn, eating more Flubenvet than they need – can you still say you’ve no egg withdrawal period and eat their eggs?

      I would slowly remove all food, leaving only layers pellets for a couple of days – when they get hungry, they will eat them, then introduce the Flubenvet wormer.

  2. Heather says:

    Hello. We worm our chickens with Flubenvet every three months and also give them Beryl’s Friendly bacteria occasionally if they look under the weather. We also give a 2% organic ACV in their water every day but we wanted to check whether this ACV could interfere with the effectiveness of the Flubenvet and/or the Beryl’s Friendly Bacteria. At the moment, we stop the ACV when we are using Flubenvet or Beryls just in case it does but wanted to check whether that is necessary/advisable and if so how long would it be recommended to stop it for? Thanks.

    • Keeping Chickens says:

      I’ve never heard of any problems. ACV and Beryl’s supports the gut so I don’t see any issue.

  3. Steve says:

    Hi just reading about flubenvet wormer.Iam about to get 4 chickens and would like to know how much flubenvet i will add to how much layers pellets for 4 birds thanks

    • Keeping Chickens says:

      Follow the advice on the pack – it is made up with a certain quantity of feed and one 60g pack makes enough for about 20 hens. If not, you can buy 5Kg sacks of pellets – if you know how much they eat in a week (remove other food during this time), then you will know how many Kg of feed you need for them. A 5Kg bag should be enough.

  4. Alma B says:

    HI, I have 15 hens and 6 pullets. They get fermented feed every morning. Would it be ok to mix the powder with their fermented feed ? I would say that they get close to 2 kilos of feed daily.

    • Keeping Chickens says:

      I haven’t used it – but I assume it would be fine providing they eat a similar amount as a hen that eats pellets.

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