Parasitical poultry worms are very common, and as long as they are monitored and, if necessary, treated with an effective wormer, they will not usually have a long-lasting effect on your birds. Infested chickens will become lethargic, and will eventually stop eating, so you need to keep an eye on the situation, and intervene with worming drugs if the outbreak is causing health problems.
Chickens can directly or indirectly ingest worm eggs. Direct ingestion means they will eat the worm egg. Indirect ingestion means they will eat an earthworm or bug that is the host of worm eggs. The parasites will then live and lay eggs inside your hens, which will pass them out through droppings, so that the pesky parasitical lifecycle begins again.
If your chickens are infected it is much easier to get rid of the worms if you move your chickens to a new grazing area regularly. This is so your chickens won’t be continually ingesting the worm eggs which are in your chickens droppings.
Free ranging birds like this Welsummer hen will eat worms, which may contain eggs of intestinal parasites
Most parasite worms belong to the Nematode family. As a family, nematodes are thought to be the commonest animal on the planet, with several million in a small garden plot. The ones that infest poultry are as follows:
Caecal worm (Heterakis Gallinarum)
You may not even notice the presence of these worms, as there are no obvious symptoms or bad side effects in chickens, usually. They are light grey or white, curiously S-shaped, and grow up to ¾ inch. Problems only occur if you are keeping turkeys, which can succumb to a fatal condition known as blackhead as a result of eating caecal worm eggs.
Gapeworm (Syngamus trachea).
These inhabit the birds’ trachea and lungs, making them short of breath. A gaping beak, neck-stretching and head-shaking are clues that infection may have occurred. The worms are red, and grow to more than ¾ inch in length. They come in pairs, joined to form a ‘Y’ shape.
Gizzard worm (Amidostomum Anseris).
Uncommon in chickens – this is mainly a goose parasite – they take up residence in birds’ gizzards. Chickens that live with or near geese may become infested. Affected birds rapidly lose weight. Hair worm, (Capillaria – various species). Found in the crop, oesophagus, proventriculus and intestine. They are very thin, and grow up to ¾ inch. Infected birds suffer diarrhoea and anaemia, and the birds look unwell, with a hunched posture and sagging wings. Death follows unless the condition is treated. Prevention is the best cure: keep grass short (UV light kills the eggs), and rotate the ground to avoid the build-up of trampled muddy areas, where the worm eggs thrive.
Roundworm (Ascarida Galli).
This is the commonest of the nematode worms, and the easiest to deal with via a standard wormer. The parasite inhabits the digestive system, and grows up to 8cm long. Pale egg yolks and poor egg production are symptoms that should prompt you to investigate. The worms turn up in droppings, and will eventually take over the chicken’s digestive and egg-laying systems.
Tapeworms (Cestodes family).
An intestinal parasite, and the only worm mentioned here that does not belong to the nematode family. Hard to spot, the ones that invade chickens reach just 1/6 inch in length. Infected birds will eat lots but lose weight, and their laying will be affected.
Roundworm, Gizzard worm, Hair worm and Caecal worm are all transmitted from chicken to chicken via egg-infested droppings. The eggs can lie dormant on soiled ground for up to a year. Gapeworms and Tapeworms are picked up via an intermediate host such as a slug, snail or earthworm.
General Signs of Worms in Chickens
Birds infected with worms will often eat more than usual. If you didn’t know better, you might think this was a sign of blooming good health! But the poor bird are feeding their unwanted lodgers. The chickens will also begin to lose weight (or fail to put weight on). The yolks of their eggs will be pale, and they will have loose droppings. Anemia is common too, recognizable not just through the bird’s lethargy and drooping appearance, but by a fading in the red colour of the comb and wattles. If the parasite in question is gapeworm, the chickens will have open beaks, gasping for breath and stretching their necks.
Worm Egg Count
This is something you can do with a shop-bought kit. You collect samples and send them for analysis (as the eggs are too small to see with the naked eye). It’s cheaper than a trip to the vet’s, and the point is that if the egg count is low, the infection is mild and will not have a detrimental effect on your birds. Mild outbreaks of intestinal worms are a fact of life, and your birds will just have to live with them.
"Why not just worm the birds anyway?", you may ask. Unfortunately, chickens can become drug-resistant if over-exposed to worming treatments, so it’s best to save a dose of worming until the flock really needs it, i.e. in a severe outbreak.
Minimising Worm Infestation
Worms are a fact of life in the late Spring and Summer. Their eggs lie dormant if the ground is too dry, too cold (below 50F) or too hot (above 95F).
You’ll never avoid parasitical worms completely, but you can minimize the chances of major infestation as follows:
- Don’t allow wet, warm, muddy areas to develop in the chicken run. This is the ideal breeding environment for worm eggs. Gravel, or stone/concrete areas overlying the wet ground should be considered.
- In sunny weather, Ultra-violet Light (UV) from the sun will destroy worm eggs in short grass. Keeping the grass short in the area the chickens forage on will enable the sun to do its work.
- Try to rotate the ground too, moving the birds from one area to another, to prevent a build up of worm eggs in one spot.
- Change the wood shaving or straw litter in the chicken shed fresh and dry.
There are several "gut sanitizers" available on the poultry market. Some are herbal, or use all-natural ingredients, while others take more of a chemical warfare approach! For the benefit of the food chain, including your own consumption of chicken products, it’s best to stick to the more natural ones, as long as they do the job.
One old remedy for worms is a small amount of apple cider vinegar in the birds’ water. They don’t seem to notice it, but worms are thought to evacuate any gut that’s rinsed out with the vinegar. Garlic is an alternative, crushed into the chicken’s water supply. These preparations can be sprayed on infected ground too.
You can also buy sanitizing powders which absorb moisture from the ground, the chicken droppings and from the worm eggs.
Any worming endeavor should be repeated two or three weeks after the first treatment. This will catch worms which were not yet hatched when you first applied the treatment. Hair worm and Roundworm have longer lifecycles, and the treatment should be repeated every two weeks for up to six weeks.