What are Roundworms?

Nematodes can vary in size and shape, and can cause different symptoms dependent on where they choose to live within the host. What all species of roundworms share is the method of transmission. Adult roundworms will lay eggs inside an infected bird. The eggs are passed through the feces, where they can incubate in soil. Eggs can be directly ingested by a healthy bird, or by an intermediate host, often in the form of an insect, which is then eaten by the bird. Often, symptoms of an infection are absent, allowing an infected bird to shed eggs for long periods, infecting others.

Roundworm infections are common in poultry, wild birds, and companion birds. The various species of roundworms, or nematodes, can infect various tissues and organs inside your bird’s body, including the gastrointestinal tract, eyes, proventriculus and ventriculus, the body cavity, and air sacs. Untreated, roundworms can cause significant damage to the tissues in which they live, causing death by tracheal ulceration or asphyxiation.

Symptoms of Roundworms in Birds

Symptoms can vary, and will depend on the type of roundworm that your bird is infested with, as well as the area of the body where the worm lives. Symptoms include:

  • Inactivity
  • Loss of condition
  • Weakness
  • Depression
  • Diarrhea
  • Dark, sticky feces containing blood
  • Droppings pasted near vent
  • Loss of appetite
  • Coughing
  • Open mouthed breathing
  • Pneumonia
  • Difficulty swallowing
  • Regurgitation
  • Vomiting
  • Dried blood at beak 
  • Increased vocalization
  • Intestinal obstruction 
  • Weight loss
  • Emaciation
  • Pale oral mucous membranes
  • Eyelid spasms
  • Poor feather quality, such as dull or dark colored 
  • Growth abnormalities
  • Loss of body movement control
  • Head shaking
  • Abnormal head or neck position
  • Disturbed vision
  • Masses on legs and feet 
  • Difficulty breathing
  • Death


There are many types of roundworms that can infest birds. Some of the types of these nematodes include:

  • Ascarids – Common in budgerigars, cockatiels, and psittacine; also found in many birds who have access to the ground
  • Capillaria – Tiny thread-like worms that infect the gastrointestinal tract of many companion birds, such as macaws, canaries, budgerigars, pigeons, and gallinaceous birds
  • Spiruroidea –These infect the intestines of cockatoos, parakeets, parrots, and macaws, and include four types of eyeworms
  • Syngamus – These are rarely found in companion birds, but are more common in galliformes and anseriformes
  • Filariidea –These populate the eyes, heart, joints, organs, and subcutaneous tissues of cockatoos and psittacines


Causes of Roundworms in Birds

A roundworm infection is caused by an ingestion of the eggs or larvae of any type of nematode by your bird. This can be by direct bird to bird transmission, or through an intermediate host. Roundworm eggs are passed out through the feces of infected birds, where they can infect healthy birds. Sometimes, an intermediate host will ingest the eggs and give them a host within which they can evolve into larvae. These hosts are then eaten by a healthy bird, causing a new infestation. Direct transmission can occur through:

  • Ingestion of feces, or something contaminated with feces
  • Ingestion of contaminated water

Common intermediate hosts that indirectly transmit roundworms include:

  • Flies
  • Earthworms
  • Darkling beetles 
  • Litter beetles 
  • Snails
  • Surinam cockroach
  • Earwigs
  • Grasshoppers 
  • Sowbugs


Diagnosis of Roundworms in Birds

A diagnosis begins with an examination of your bird and any symptoms present, as well as any known history of exposure to infected birds. Roundworms are diagnosed primarily by a fecal flotation, although the shedding of eggs may be intermittent and dependent on where the particular species of roundworms infecting your bird lives. 

Since many of the symptoms are similar to other conditions, your veterinarian may run other tests to narrow down a possible cause, which can include a urinalysis and bloodwork.



Treatment of Roundworms in Birds

Treatment of a roundworm infection is through the administration of anthelmintics. Particular medications can vary depending on the species of nematode infecting your bird, and could include Ivermectin, fenbendazole, or piperazine. Your veterinarian will prescribe an appropriate dewormer for your particular bird and the infecting roundworm for a set amount of time, often followed by retesting to check on the progress of your bird’s recovery. 

If your bird is infected with a roundworm that lives in the eye, a cresol solution is applied to the eye that instantly kills the worms. Eyes are then irrigated with a saline to clear away the solution and any debris. If damage to the eye is not too advanced, improvement is seen within 48 to 72 hours. 

If you have multiple birds, you should treat the other birds as well, as they likely have contracted roundworms. If your bird lives in an outdoor aviary, routine deworming, often at 6 month intervals, is recommended.



Recovery of Roundworms in Birds

Recovery from a roundworm infection is possible if treatment is begun before the worms have caused permanent damage to the internal tissues of your bird. If left unchecked, roundworms can be lethal. Be sure to have your bird checked after encounters with new birds, or after eating insects and other possible intermediate hosts from outdoors. Prevent your bird from contracting roundworms through good hygiene practices, such as:

  • Keeping feeders and waterers clean
  • Not allowing birds to eat off the ground by always placing food into appropriate feeders
  • Preventing birds from eating earthworms, or other possible hosts
  • Avoiding overcrowding birds
  • Using routine dewormers
  • Performing routine fecal flotations to check for infestations


Roundworms Questions and Advice from Veterinary Professionals

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© 2022 Wag Labs, Inc. All rights reserved.