Worming Chickens: Spot, Treat And Prevent Worms

Worming Chickens

Worming chickens is an essential part of keeping your flock healthy. Intestinal worms are more common than many backyard keepers realise, and if left untreated, they can cause health issues, reduced egg laying and, in some cases, serious illness. In this post, I’ll explain how to spot a worm problem in your hens, what to use to treat it, and how to stop it coming back.

Why worming matters

Internal parasites like roundworms and gapeworms live inside your hen’s body, stealing nutrients and causing damage along the way. Even a light burden can affect egg laying, weight and condition. Heavier infestations can lead to more serious illness or death. I’ve seen hens with clear signs of worms perk up quickly after proper treatment, so it’s worth staying on top of it.

Common types of worms in chickens

There are a few types to watch for in UK flocks:

• Large roundworm (Ascaridia galli) – These are the most common. They live in the small intestine and can grow several centimetres long. Recent research shows that A. galli has become more widespread in commercial flocks since the end of battery cages, which tells us just how persistent they can be.
• Caecal worm – Often harmless on its own, but it can carry blackhead disease, which is fatal to turkeys and can sometimes affect chickens too.
• Gapeworm – Lodges in the trachea (windpipe), causing chickens to cough or gasp for air. It’s not common in small flocks, but worth knowing about.
• Hairworm and threadworm – Thin and tricky to spot, these can irritate the gut and cause chronic problems if left untreated.

Signs your chickens might have worms

Some hens carry a few worms without obvious symptoms, but here are common signs that might indicate a problem:

• Weight loss or a bony keel
• Pale combs or wattles
• Diarrhoea or foamy droppings
• A sudden drop in egg production
• Gasping or gaping (especially with gapeworm)
• Worms visible in droppings (this usually means a heavy infestation)

I always say, trust your instincts. If a hen seems off and you’ve ruled out other causes, it’s worth testing for worms. You should also check for mite infestation.

How to confirm if your flock has worms

You don’t have to guess. A faecal egg count (FEC) will tell you if worms are present and how bad the burden is. You can use a poultry vet or use a service like Westage Labs, which will send you a testing kit and email the results within a couple of days. It can be worthwhile doing tests routinely – it’s a lot better than worming blindly and helps avoid overuse of medication.

How often should you worm chickens?

That depends on your setup and whether you test regularly:

• If you test – Worm only when results are positive
• If you don’t test – Treat the whole flock three or four times a year (spring, mid-summer and autumn work well)
• After a known risk – Treat if you’ve had a red mite outbreak, flooding in the run, or introduced new birds recently

Choosing a chicken dewormer

In the UK there is really only one solution for worming chickens: Flubenvet 1 %, which contains the active ingredient flubendazole.

Why Flubenvet is the benchmark

• POM-VPS licence – It’s classed as Prescription-Only Medicine – Vet, Pharmacist or Suitably Qualified Person. That means it must be sold through a registered seller who checks basic information before dispatch.
• Target species – Licensed for chickens, turkeys and geese. Not licensed for ducks, so be cautious with mixed flocks.
• Zero egg withdrawal – You can keep eating eggs during treatment, which makes life a lot easier for backyard keepers.
• Proven results – Kills all major types of intestinal worms in chickens, including roundworm, gapeworm, caecal worm and hairworm.

How to use it

1. Choose a format –
   • Premixed layers pellets are simple and ready to use
   • 1% powder tubs let you mix it into your own feed (use gloves and a mask)
2. Follow the dosage –
   You’re aiming for 30 ppm flubendazole in feed. The premixed feed is already balanced. If using powder, weigh the day’s ration and mix in the correct amount based on the label.
3. Feed for seven full days –
   Don’t offer treats, scraps or alternative feed during this period. Let the birds eat only the medicated feed.
4. Repeat if needed –
   If your faecal test showed a heavy worm burden, repeat the seven-day course three weeks later to catch anything that hatched since.
5. Clean the coop afterwards –
   Replace bedding, scrub perches and disinfect floors to reduce the chance of reinfection.

Quick answers

• Is it safe for bantams? – Yes, the dose is based on feed quantity, not bird size.
• Can I use it with chicks? – It’s licensed for birds over 16 weeks. Speak to a vet for younger birds.
• Do I need to throw away eggs? – No. There’s zero egg withdrawal for Flubenvet when used correctly.
• Can I get it on Amazon? – Possibly, but many listings aren’t from licensed sellers. To stay compliant and safe, I recommend buying from a UK-based SQP or vet-approved retailer.

Preventing worms in the first place

Good hygiene goes a long way when it comes to preventing worm problems:

• Rotate the run or rest it when possible
• Rake up droppings regularly
• Raise feeders and drinkers off the ground
• Don’t let wild birds or rodents access the feed
• Keep bedding dry and change it often
• Offer grit year-round – it helps the gizzard grind up worm eggs
• Use faecal egg counts to check if treatment is really needed

I also add mint and oregano to the run when they’re in season. They won’t cure worms, but they do discourage some insects and help keep the run fresh.

Final thoughts

Worming chickens doesn’t need to be complicated, but it does matter. A good testing routine, clean living space and the right treatment when needed will help your hens stay healthy and laying well. If you’re not sure when your flock was last wormed, it’s probably time to check.

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Disclaimer: This article provides general information and is not a substitute for advice from a poultry veterinarian.