RoundWorms (Ascarids)

One type of internal parasite that affects poultry is roundworm.   Roundworms are caused when the bird ingests eggs found in contaminated earth, feces or water.  The most common symptoms of roundworms are lethargy, pale comb/face, weight loss, diarrhea and drop in egg production.  In extreme cases death may occur.  Roundworms are the most common type of parasitic worm found in poultry.  Roundworms are extremely prevalent in backyard and free-range flocks.   Control of worms is very important for the general health of your flock, as the presence of worms can reduce the birds' immunity to other diseases. 


Who:  All birds including:

  • Chickens
  • Ducks
  • Geese
  • Turkeys
  • Game Birds
  • Pigeons

Where:  Worldwide. 

When:  Young birds are more susceptible, however adult birds can also be affected. 

Why:  Ingestion of viable eggs which can be found in contaminated droppings (fecal matter), earth/soil, bedding and water.  


  • Consumption of viable roundworm eggs.  
  • Ingested roundworm eggs are able to mature inside the bird's small intestine.      


  • The roundworm life cycle is as little as 35 days from egg to mature reproducing adult.  
  • Eggs mature to adulthood inside the birds' small intestine. 
  • Adults roundworms (at approximately day 35) then lay eggs are produced which are then passed through the feces, where they can be consumed by other birds, and therefore can rapidly spread throughout the flock.  
  • Roundworms vary in size from large visible worms (usually 1-3" long) to microscopic worms.   They can usually be seen in feces, however not all varieties are visible to the naked eye.  

            Common Symptoms:

              Other  Symptoms:


Medicinal Treatments -  Need to be repeated according to label instructions to account for the hatching cycle of the eggs: 

  • Wazine-17 (Piperazine)   (requires a withdrawal period of 14 days) - 1 oz/gallon of water - For best results, remove non-medicated water in the evening and replace with medicated water to assure all birds get sufficient treatment.  All unused medicated water should be removed at the end of the day.  Needs repeated at least once after 3 weeks. It may be advisable to repeat this course of treatment 2x yearly as preventative maintenance.   Follow this link for very detailed instructions for the use of Wazine-17:
  • Ivermectin (Ivomec is a brand name for the same product) Use only under the supervision of an avian veterinarian.  These are not approved for use in food producing  animals,  however a veterinarian may prescribe it at their discretion.   (See link at the bottom of the page.)   
  • Vitamin A - used as a supplement it can speed recovery of intestinal damage caused by roundworms.

            Note:  Always follow the label instructions and/or your veterinarian's recommendations.  

Natural Treatments: 

  • Garlic  (added to water; some birds may eat minced garlic in the feed or on the ground) 
  • Chopped pumpkin seeds
  • Chopped cucumber seeds   
  • Apple Cider Vinegar (added to water)
  • WormGuard Plus - Contains Diatemaceous Earth

            Note: Poultry Heath Central makes no claims as to the efficacy of these natural treatments, however many flock owners claim that they are effective alternatives to medicinal treatments.   They are probably best used in preventative flock maintenance, however if your birds are shedding worms in their feces a course of medicine is recommended to restore their health.  


Vaccine:  No

  • Sanitize coop regularly. (Eggs are not deterred by temperature or sprays so bedding needs changed regularly)
  • Keep young birds separate from older birds.
  • Keep birds on wire mesh floors where exposure to contaminated droppings can be minimized.


Also Known As: 

  • Nematodes
  • Ascarids

Affects:  Small intestines

Clinical Diagnosis:  So common in poultry that the presence of worms can nearly be assumed.  Older birds can tolerate several worms without any negative effects.  Younger birds (2-3 month old) are most susceptible and are most negatively effected.  Observation of the worms in the droppings is the most sure indication.  Large visible roundworms are white, 1-3 inches long and look somewhat like spaghetti.

Diseases with similar symptoms:  Some external parasites (Mites, lice, etc.) can cause LethargyPale comb/faceWeight loss or retarded growth.  

Duration of symptoms:  Ongoing until the flock is successfully treated.  

Morbidity:  High

Mortality:  Low, except in severe infestation

Transmission to people:  None known


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A righteous man cares about his animal's health...

Proverbs 12:10a