Do chickens need deworming?
Chickens that live on the ground, scratch in soil, and eat insects will almost always be exposed to internal parasites. Roundworms, gapeworms, tapeworms, and threadworms are among the more common ones. A light worm burden often causes no obvious trouble. A heavy one can interfere with nutrient absorption and may affect health, growth, and egg production.
That means the question is not “do I deworm on a schedule” but “do my birds have a worm problem, and how do I manage it?” Many keepers and vets prefer testing before treating, and managing the environment so worms have a harder time spreading.
Note that few dewormers are labeled specifically for chickens, particularly in the United States, so using one usually involves off-label decisions best made with a vet. This article is general information and not veterinary advice.
Signs your chickens may have worms
Worms are not always visible, and signs are often vague. Possible clues include:
- Weight loss despite a good appetite
- Pale comb or lethargy
- Drop in egg production or thin-shelled or small eggs
- Loose or abnormal droppings
- Poor feather condition
- Visible worms in droppings or, occasionally, in eggs (this is unpleasant but does not necessarily mean heavy infestation)
- For gapeworm: gaping, head shaking, or noisy breathing
Many of these signs overlap with other problems, including coccidiosis, mites, poor nutrition, and age-related changes. That is why guessing is risky. See our overview of watery chicken poop for other causes to consider.
Get a fecal test first
A fecal float test, done by a vet or sometimes a diagnostic lab, can detect worm eggs in a fresh dropping sample and also coccidia. It does not catch everything, such as some worm stages, but it provides far more information than guessing. Collect a few fresh droppings from different birds or from under the roost, store them according to the lab’s instructions, and bring them in.
A test also helps you avoid unnecessary treatment, which matters because overuse of dewormers contributes to resistance in parasites over time.
What “natural” can and cannot do
Natural dewormers include seeds, herbs, and plant-based supplements. Their appeal is clear: easy to find, familiar, and seen as gentler. But claims around them often outpace the evidence. Lab studies of plant compounds do not always translate into reliable results in live birds, and doses in commercial herbal mixes are not standardized. Reviews and testimonials on product pages are not evidence.
In practice, the approach with the strongest support is management that interrupts the worm life cycle. Supplements may play a minor supporting role at best, and they are not a substitute for treatment when a bird is actually sick.
Management steps that reduce worms
- Rotate or rest ground. Moving birds to clean ground, or resting a run, helps break the parasite life cycle. Birds kept on the same ground all year tend to have a higher parasite risk.
- Keep litter and ground dry. Damp, dirty areas help worm eggs survive.
- Clean up manure. Remove droppings from roosts and runs regularly.
- Avoid overcrowding. More birds on the same ground means more worm eggs.
- Raise feeders and waterers so birds are not eating off contaminated ground.
- Quarantine new birds and consider testing them.
- Keep chicks away from adult birds’ ground until they have grown.
- Control intermediate hosts, such as slugs, snails, and flies, where practical, because some worms spread through them.
- Test regularly, for example once or twice a year or when you see signs.
Common natural options
Pumpkin seeds
Pumpkin seeds are widely recommended and contain a compound called cucurbitin, which has been studied for its effect on some parasites. Chickens usually enjoy them, and they are a harmless treat. Whether they meaningfully reduce worms in a flock is not well established, so treat them as a nutritious snack rather than a dewormer.
Garlic
Garlic is commonly added to feed or water. It is generally considered safe in modest amounts, but evidence that it clears worms is weak. Large amounts could taint eggs or irritate the gut, so use sparingly.
Herbs, wormwood, and black walnut hull
Herbal blends often include wormwood, thyme, oregano, or black walnut hull. Some plants contain compounds that are toxic in high doses or have unclear safety for hens, particularly wormwood and black walnut. Dose is not standardized in commercial products. If you want to use them, talk to a vet first, and avoid giving them to chicks or sick birds on your own.
Diatomaceous earth
Diatomaceous earth is often used as a feed additive or in dust baths. Evidence for internal worm control is limited, and the dust can irritate lungs, so avoid creating clouds of it.
Apple cider vinegar
ACV in the water is a popular choice but is not a dewormer. We explain what it can and cannot do in our article on apple cider vinegar for chickens.
What happens if you don’t deworm?
Often, nothing dramatic. Many backyard flocks carry some worms and remain healthy. Risk rises when birds are crowded, kept on the same ground long-term, young, stressed, or in poor condition. In heavy infestations, birds can lose weight, lay less, become weak, and in severe cases die. Some worms, such as gapeworm, can cause breathing problems. If you see signs, test and talk to a vet rather than waiting.
When natural is not enough: veterinary dewormers and egg questions
When tests show a significant worm burden, or birds are visibly affected, a vet may recommend a prescription or off-label dewormer. Because few products are approved for laying hens, ask your vet about the correct product, dose, repeat treatment, and how long to hold eggs, if at all. Do not assume that “natural” means no withdrawal question, or that “chemical” always requires one. Rules vary by country and product.
Also consider that treating without clearing the environment may lead to quick reinfection, so combine treatment with the management steps above.
When to see a vet
See a vet if:
- A bird is losing weight, weak, or has a pale comb.
- Birds are gasping, gaping, or shaking their heads.
- Worms are seen in droppings or eggs and the bird looks unwell.
- Several birds are affected, or you have unexplained losses.
- Droppings are bloody (see chicken pooping blood and coccidiosis) or persistently watery.
- A bird has a swollen belly (see why a chicken may be bloated).
FAQ
Do pumpkin seeds really deworm chickens?
They are a healthy treat, but there is not enough reliable evidence to count on them to clear a worm infection.
Will apple cider vinegar deworm chickens?
No. It may have minor effects on water quality and some keepers like it as a tonic, but it should not be relied on for worms.
How do you tell if your chickens need to be wormed?
Look for weight loss, pale combs, and drops in laying, then confirm with a fecal test. Signs alone cannot confirm worms.
Are natural dewormers safe?
Not automatically. Some herbs are toxic at higher doses, and products vary. Check with a vet, especially for chicks, sick birds, or birds that you are treating with other medication.