Worming Options y for Chickens and Other Poultry

There is only one licenced wormer available over the counter for poultry. Flubenvet, based on the active chemical Flubendazole is a prescription only medicine that can be sold by Vets, Pharmacists and SQPs or RAMAs (Suitably Qualified Persons or Registered Animal Medicine Advisors).

Additionally Fenbendazole is a similar chemical that is licenced for avians in the UK under the brand names Gallifen or Panacur aquasol. This is a prescription medicine only available from your vet.

The limited nature of the chemicals available to treat parasites in birds makes it even more important to target them appropriately and use them only when necessary to slow the development of resistance. Every exposure to a chemical, whether warranted or not, aids this process and, once resistance develops, worms never regain their sensitivity leading to increasing disease and deaths caused by untreatable parasite burdens.

Once we have established it is time to step in with a treatment, what is the most effective way to administer it?

chickens eating


Over the Counter

Flubendazole is the only licenced POM-VPS wormer for avians in the UK. For the domestic chicken keeper (under 50 birds, no sale of meat or eggs) Flubendazole comes either as ‘final medicated feed’ or as a ‘premixture’ to combine with feed.

Effective against: gapeworm, large roundworm, caecal worm, hairworm, and gizzard worm in chickens, turkeys, and geese. Activity includes adult worms, larvae and eggs.

This medication is not licensed for tapeworm (though a vet may prescribe a double dose as there is some thinking it may be effective for some species on this regimen), nor is it effective against Cocci (Eimeria spp.) or Blackhead (Histomoniasis meleagridis) protazoas.

Replace ALL food with flubendazole medicated feed for 7 days - that unfortunately means no supplementary mix or treats! The birds will eat the correct dosage for their size during this time, larger birds eating more. Medicated feed has a shelf life of approx. two months.

Meat withdrawal seven days - Zero withdrawal period for eggs.

Following treatment for a high worm egg count the advice is preferably to reduction test 10-14 days later by doing another worm egg count or to give another course of medicated feed three weeks later.


Final medicated feed for poultry

Final medicated feeds are the easiest to administer. These are proprietary mixtures of hen food that already contain the recommended dose of wormer. They are easy to use and can be bought of the shelf. As a general rule of thumb 20kg of feed is sufficient for 20 large chickens for one week.

MEDICATED premixture

Chicken wormer

Flubendazole Premix also comes as a powdered formulation available to the domestic poultry owner at a strength of 1% and in tub sizes of 60g and 240g. At 1% one 60g tub will medicate 20kg of feed. Each 6g scoop is sufficient to prepare 2kg of food. 

Measure out 2kg of your normal poultry feed, eg. layers pellets or mixed corn. From this take out a mug full and mix in 1 scoop of Flubendazole. Pour this into the remaining 2kg of feed and mix evenly. Feed this 2kg of feed to the birds over 7 days. 
Some keepers mix the flubendazole with a little oil first to help it stick to the pellets and prevent dust. If you choose to do this use only a small amount so as not to make the pellets soggy and be aware it will make the food spoil sooner.


There is NO SQP treatment for food chain animals. Vets can be hesitant to treat healthy birds, strict rules for egg withdrawal for own consumption must be observed and you cannot sell your eggs for human consumption following use.
  1. Severe infection + 50,000 e.p.g. and symptoms discuss treatment with an anti-coccidial medication with Vet. Usually Harkers Coxoid or Baycox. Both POM-V, Harkers GSL for pigeons
  2. Antibiotics to control the bacterial disruption to the gut
  3. Keep the bird warm and dry, offer pre and probiotics to restore gut flora, using apple cider vinegar in the water help to strengthen birds against infection and providing a multi vitamin supplement.
  4. Disinfect the hen house to kill eggs in the environment, supply good ventilation and keep the bedding as dry as possible.
There are products like Bokashi Bran, Gut Conditioning Pellets and Gastric Grit that Clare Taylor sells that are good for this.

A Note on Geese

Geese are grazers which can make it difficult to ensure they get a full dose of medicated feed – alternatives such as levamizole* and fenbendazole are available POM-V on cascade.

Gizzard worm and gapeworm are the two most prevalent parasites of geese. Keeping geese and ducks on fresh pasture and testing them regularly will help to manage infection. Pay particular attention to young goslings around 12 weeks.

Geese are defined as poultry and so flubendazole is a licensed product.

*some documented gapeworm resistance

A Note on Pigeons 

Primary parasites of concern are: Roundworm (Ascaridia columbae), Hairworm (Capillaria obsignata), Tapeworm (Hymenolepis columbae, Raillietina columbae) and Cocci (Eimeria sp.)

CANKER or Trichomoniasis is a protozoan parasitic disease primarily of pigeons that causes lesions/necrosis of respiratory tract and symptoms of gaping. In acute form birds lose weight rapidly, become weak and listless, and die within 8–10 days. Infection is confirmed by saline wet mount or culture.

Pigeons aren’t food producing animals so the licensed products differ to poultry:

> Wormers: Levamisole sold as Harka-Verm and in Harkers 3in1 and Liquid moxidectin (also treats lice and mites)

> Anti Coccidials: Amprolium

> Canker: Ronidazole

A Note on Ducks

Ducks are fairly disease resistant when good husbandry and management techniques are practiced. A classic sign of ducks having worms is that they will ‘go off their legs’ or go lame.

Primary parasites of concern are: 
Roundworm (Ascaridia galli), Gapeworm (C. bronchialis S. trachea), Gizzard Worm (Amidostomum anseris), Tapeworm - various and Caecal Worm (Heterakis gallinarum).

There are no licensed wormers for ducks in the UK, any treatment needs to be on cascade through vet only.