You’re most likely going to be aware that your flock has round worms (Ascaridia galli) when you spot what looks like 2”-3” rubber bands in their poop (they can actually grow longer!). I occasionally see a worm or two in poop, but a few weeks ago, I noticed a four-week-old chick passing a number of them. Seeing such a small chick with that level of intestinal worms grossed me out. That was my cue to treat the whole flock to get rid of what was in their system and start again with a level playing field.

I don’t free-range my birds anymore; they are confined to two pens (1200 square feet and 480 square feet). There are downsides to free ranging, but one of the main benefits is they are less likely to have worms than penned birds. Those with access to a large territory are always on the move, foraging and spreading their poop far and wide. That last practice is important because that’s one of the ways round worms are spread. They are not transmitted by adult worms so you don’t need to worry about the ones you find expelled in their poop; it’s the eggs that get ingested through pecking in the soil that are the problem. They can also pick them up through eggs in poop that have contaminated water or feed containers or by eating earthworms.

Roundworms are the most common type of worm and do the most damage to chicks. By the time birds are about four months they are starting to develop resistance to worms and by adulthood they can often live with some worm load with no ill effects.

We’re never going to eradicate all intestinal parasites – the goal is to keep them in manageable numbers. Like with all parasites ,the heavier the worm load and the younger the bird, the more potential damage that can be done. Round worms can cause partial or complete obstruction of the intestine, resulting in reduced gastrointestinal movement and delayed crop emptying.


The roundworm lifecycle is relatively short: adult female worms can lay a whopping 200,00 eggs daily that pass out of the host’s intestinal tract with their poop. While in the coop shavings or in the soil the eggs develop to the larval stage. Our birds ingest the developed eggs and once inside their body larvae are released from the egg and travel to the intestinal tract where they develop in the intestine’s mucosal lining. By the time they are 18 days old they are infective. Just a few weeks later, when they are 35 days old they are sexually mature and ready to start the next generation. A roundworm can live up to two years.

Roundworm in Egg
Roundworm Inside Chicken Egg


  • Undigested food in poop
  • Diarrhea
  • Decreased growth in young birds
  • Reduced appetite
  • Pale comb and wattles
  • Reduced amount of poop
  • Delayed crop emptying (often mistaken for crop issues)


  • Maintaining good sanitary practices: regular cleaning and removing droppings reduces opportunities for birds to ingest worm eggs.
  • Avoid overcrowding.
  • Worm and quarantine new birds.
  • Provide apple cider vinegar in drinking water (1 tbsp./gallon of water) a couple of times per month. Only use non-galvanized drinkers; ACV will rust metal.
  • Add crushed garlic to their drinking water
  • If your birds are penned try to rotate between different areas to minimize build-up of worm populations.
  • Elevate feeders and waterers to discourage fecal contamination.
  • Use nipple waterers, which are less likely to be contaminated with poop.
  • Clean and disinfect equipment daily.
  • Be careful with chicks, which are more vulnerable to the negative effects of parasites. (Keep them segregated and disinfect their equipment often)
  • Treat broody hens as soon as they start sitting to rid them of their worm load prior to their chicks hatching.
  • Make sure your birds have a diet rich in vitamins A and B, which makes them less vulnerable to worm infections. (vitamin A: sweet potatoes, carrots, spinach, broccoli, cantaloupe and pumpkin. Vitamin B: whole grains, eggs, yoghurt, seeds, dark leafy greens, bananas, fish/meat and legumes).
  • The deep litter method is associated with intestinal parasites because poop is allowed to build up and the birds have access to it for longer periods of time.
  • Avoid feeding directly on the soil.
  • Dispose of coop shavings and bedding where your birds don’t have access to it

Parasitic Worms

Treatment (I live in Canada. Different jurisdictions may recommend and have different medications available. Often wormers for chickens are used off-label. Talk to your vet for advice about the most appropriate product and egg withdrawal periods).

  • Treat all birds at the same time
  • Piperazine/Wazine: 1 tsp/1 gallon water in the only source of water for one day. Repeat in 10 days.
  • Ivermectin: apply topically, repeat in 10 days.
  • Fenbendazole/Panacur (paste, powder or liquid)
  • Abendazole
  • Safeguard

I’m not very knowledgeable in the use of herbs to treat parasites, but there is clear evidence that many alternatives to insecticides are effective, including the use of turmeric and wormwood. This article provides more detailed information.


0 comments on “Roundworms

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Bitchin' Chickens

Everything You Need To Know About Small Flock Chickens & More

%d bloggers like this: