Warmer weather creates wonderland for worms this year

While chicken keepers may have enjoyed the mild temperatures last winter, many poultry parasites may have flourished during the warmer weather too. An increased worm challenge puts chickens at greater risk of poor health and reduced egg production; even affecting birds which seem to be fit and well. This makes the end of summer a key time for keepers to review their worming regimes to future safeguard their chickens’ health and welfare.

Although worms pose a potential threat to free range chickens all year round, winter has traditionally been a time of year when parasites fail to thrive and the worm challenge is reduced. However, the above average rainfall and higher temperatures experienced in the UK last winter1 provided conditions that worm eggs need to survive. This warmer winter could potentially mean we are now faced with a greater risk from these parasites.

But what does this mean for chickens and their keepers? There are a variety of worms which can commonly infect poultry; many of which can be harmful to chicken health.

While the increasing day length should see egg production following suit in terms of eggs numbers produced, worm infections can actually cause a reduction in the number and quality of eggs as well as preventing young chickens from reaching their full potential as they approach point of lay.

Often there are no visible signs that a chicken is affected, and because worm eggs are not visible to the naked eye, the problem can be difficult to detect. The eggs of many poultry worms can also survive for long periods outside of the chicken, especially when weather conditions remain favorable. This means that a high level of environmental contamination can build up quickly and remain unnoticed. The longer chickens go untreated or treated with an ineffective product, the more worm eggs will be shed into the surroundings making eliminating the disease a potentially challenging and costly process for keepers.


A good worming strategy is crucial to help prevent the build-up of worms. Carefully choosing the correct wormer and applying a strategic worming regime throughout the year can be the most economical way of boosting production as well as preserving chicken health. This means selecting a licensed product with a proven active ingredient from a reputable provider and treating frequently enough to prevent eggs being shed into the surroundings - something which can occur as soon as six weeks following treatment with any wormer.

There are many factors which will affect the necessary worming frequency such as; the size of the flock, the established environmental contamination and the amount of free-range access, so professional veterinary advice should be sought when planning parasitic worm control to best tailor the treatment plan to the flock.