Worms in Chickens: What Every Backyard Poultry Keeper Should Know

Keeping chickens almost guarantees that worms will appear at some point. Chickens spend much of their day scratching through soil, insects and droppings, which means they constantly encounter parasites that live naturally in the environment. Small numbers of worms are quite common and birds may carry them without showing obvious symptoms. Trouble begins when those numbers increase and create what poultry keepers refer to as a worm burden.

A worm burden means parasites are present in high enough numbers to begin affecting the bird’s health. Worms live inside the digestive tract and feed on nutrients intended for the chicken. As the burden grows, birds may lose condition, egg production may drop and overall health can decline.

Routine worming is common practice in backyard flocks. Many poultry keepers treat their birds every quarter, roughly every three months. The change of seasons provides an easy way to remember. Autumn, winter, spring and summer offer convenient reminders and the timing broadly aligns with the life cycles of many poultry parasites.

Effective parasite control involves more than simply following a calendar. Understanding which worms affect chickens and how different treatments work helps ensure the right product is used when it is actually needed.
 

The Most Effective Wormer for Chickens

Products containing flubendazole are widely considered the most effective worming treatment for chickens. Available on the Australian market are Elanco Flubenol, Vetsense Fluverm, Laucke Red Hen Dewormer and Vella Stockfeed Chicken Wormer MP.

Flubendazole is the only approved poultry worming ingredient that treats all common intestinal worms affecting chickens. These include roundworms, hairworms, caecal worms and tapeworm. The product is also approved for use in egg-laying chickens with no egg withholding period when used according to label instructions, which makes it particularly practical for backyard flocks.

Treatment requires the medicated feed to be provided for approximately seven consecutive days. Birds must consume the treated feed consistently during this period. Treats should be avoided and free ranging should be limited wherever possible. Other food sources reduce the amount of medicated feed consumed and can reduce the effectiveness of the treatment.

Seven days of consistent feeding ensures the medication can interrupt the worm life cycle and remove parasites effectively.
 

Other Approved Worming Ingredients

Other ingredients are approved for use in chickens but they treat a more limited range of parasites.

Levamisole has been used in parasite control since the 1960s and remains a common poultry wormer. The ingredient works by affecting the nervous system of the worm, causing paralysis so the parasite loses its grip inside the digestive tract and is expelled.

Levamisole is effective against several common poultry worms including roundworms, hairworms (also called threadworms) and caecal worms. Tapeworm, however, is not affected by levamisole. Flocks affected by tapeworm therefore require a different treatment option.

Piperazine is another ingredient sometimes used in poultry worming. The compound has been used for parasite control since the 1950s and is particularly effective against roundworms, especially the species Ascaridia galli. Piperazine works by paralysing the worms so they are expelled naturally through the digestive system, although treatment range is very narrow.

Piperazine only treats roundworms and does not control hairworms, caecal worms or tapeworm. The limitation means the product is generally only suitable where roundworms are the confirmed parasite problem.

Understanding which worm species are present can therefore make a significant difference when selecting the most appropriate treatment.
 

Other Products Used by Poultry Keepers

Discussion within the poultry community often includes a range of other parasite treatments. Some of these products are designed for different animal species or for ornamental birds rather than poultry raised for eggs or meat.

Use outside the approved label directions is referred to as off-label use.

Aussie Chook Supplies does not recommend any products that aren't specifically approved for use in chickens/poultry or provide dosing advice for off-label medication use. Veterinary advice should always be sought when considering treatments that are not specifically registered for poultry to be informed about risks vs. benefits and any withholding periods that may apply.

The complete range of worming products available for poultry can be found on the Aussie Chook Supplies website.
 

Common Worms Found in Chickens

Several different worm species can infect poultry. Each parasite has its own life cycle and affects a different part of the digestive system.
 

Roundworms (Ascaridia galli)

Roundworms are one of the most common parasites seen in chickens. These worms live in the small intestine and can grow surprisingly large, sometimes reaching 10 to 12 centimetres in length.

Eggs are passed in droppings and can survive in soil or litter for long periods. Infection occurs when chickens ingest these eggs while scratching through contaminated ground. Large infestations compete with the chicken for nutrients and may interfere with digestion.

Tapeworms (Cestodes)

Tapeworms anchor themselves to the intestinal wall using hook-like mouthparts. They grow by producing body segments that gradually break off and pass out in droppings. These segments often look like small white grains of rice and are one of the more visible signs of infection.

Unlike many other worms, tapeworms typically require an intermediate host such as snails, slugs or insects before they can infect a chicken. Birds become infected when they eat these hosts while foraging, which is one reason tapeworms sometimes appear in free-ranging flocks.
 

Hairworms or Threadworms (Capillaria)

Hairworms are extremely thin parasites capable of infecting several areas of the digestive tract including the crop, oesophagus and intestines.

Some species rely on earthworms during their life cycle. Chickens therefore pick up infections while scratching through soil where infected earthworms are present. Heavy infestations can irritate the digestive tract and interfere with nutrient absorption.
 

Caecal Worms (Heterakis gallinarum)

Caecal worms live in the caeca, which are pouch-like sections of the digestive tract near the large intestine. Chickens often tolerate these worms reasonably well and may show very few symptoms.

The reason they still matter is that they can carry another parasite responsible for Blackhead disease in turkeys. For this reason chickens and turkeys are generally best kept separately, as what is a minor issue for chickens can become a serious disease problem for turkeys.
 

Natural Worming Methods