Poultry worms can cause weight loss, diarrhoea, reduced productivity, anaemia, and even – in serious cases – death. Yet many smallholders are unaware of the need to treat their poultry regularly with a medicated wormer to tackle these pernicious parasites. So what do they need to know?

According to Diederik van Rijn, founder of veterinary pharmaceutical firm Kernfarm, there are four main types of worms to look out for:

  • Roundworms (Ascaridia Galli), which are white and 5 to 8cm long. These are the most common worm and live in the middle intestine, causing gut damage, blockage, and inflammation. Symptoms include diarrhoea, weight loss and pale, anaemic combs and reduced egg production.
  • Hairworms (Capillaria) are small and barely visible to the naked eye. These worms live in the upper digestive system and cause appetite loss, weight loss, diarrhoea and dull or depressed birds.
  • Caecal worms (Hetarakis Gallinarum) live in the caeca of the gut and don’t cause any particular problem on their own bar yellow droppings. However, they carry another parasite; Histomonas, which in turn can cause Blackhead, and leads to increased mortality in a flock due to liver damage.
  • Gapeworm (Syngamus trachea) are perhaps the most recognisable but least common worms. They live in the trachea and cause gasping, head shaking and respiratory issues.

“All birds are likely to get worms at some point – but quite often smallholders aren’t aware of the risks,” explains Sophie Wilkinson, veterinary adviser at VioVet. As well as the immediate damage caused by the intestinal parasites, they can also lead to secondary infections as bacteria can pass through the gut wall more easily. Producers may also see an increase in vent pecking as well as reduced egg productivity and shell quality.

Practical measures

Worm eggs thrive in wet, warm, muddy areas, and they cannot develop when it is very dry, below 10˚C or above 35˚C. They are also destroyed by ultra-violet light from the sun, so there are practical changes producers can make to reduce the worm pressure, says Ms Wilkinson.

“Clean out coops regularly with disinfectant, and keep the bedding clean and dry. Also, move the run around onto fresh grass if possible.” Keep the grass short to maximise exposure to the sun, and try to remove muddy areas by creating hard standing or using free draining gravel.


Even with these measures, poultry are still likely to pick up internal parasites, so it’s important to check them regularly. This means taking a faecal sample and sending it off to identify the number and type of worms present. “Do this every three months, and if there is an issue treat the birds with a medicated wormer,” she explains. “If there is a high worm burden I’d treat them again three weeks later.”

Many smallholders like to use herbal products to boost bird health, but these are not proven to work against worms, she adds. “A licensed, medicated wormer must be clinically proven to work – and until recently there was only one anthelmintic recommended for use in poultry.”

A cost-effective alternative

However, there is now a second choice, which means medical treatment does not have to be too costly. The new wormer – Flubendazole 1% – is medically exactly the same as the existing market leader, but is considerably cheaper, saving poultry keepers up to 25% in price. “Using a medically proven wormer is the only way to effectively treat infected birds,” explains Mr van Rijn.

Made specifically for small holders of chickens, geese and turkeys, this anthelmintic is effective against gapeworm, large roundworm, caecal worm, hairworm and gizzard worm. Activity includes adult worms, larvae and eggs – targeting the whole worm life cycle.

Given in feed, it is easy to administer, and there is no egg withdrawal period, so eggs can still be eaten during the treatment, he adds. “Everyone wants their birds to be healthy and productive, and they can now ensure that without breaking the bank.”