Gastrointestinal parasitism in canaries (roundworms)
Gastrointestinal parasitism caused by roundworms (nematodes) is very common in canaries kept in cages or aviaries. The most frequently encountered parasites are ascarids (Ascaridia) and capillaries (Capillaria). They live in the bird's int...
What is it?
Gastrointestinal parasitism caused by roundworms (nematodes) is very common in canaries kept in cages or aviaries.
The most frequently encountered parasites are ascarids (Ascaridia) and capillaries (Capillaria). They live in the bird's intestines and feed at its expense.
This parasitic infection mainly affects young birds, those living in groups, or in facilities where hygiene is poor. It can go unnoticed for a long time before signs become apparent.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Related signs — each one links to its page:
In the early stages, the infected bird often shows no visible signs.
Over time, progressive weight loss may be observed despite maintained appetite, or conversely, a decrease in appetite.
The plumage becomes dull and ruffled, the bird appears less active and often stays puffed up at the bottom or top of the cage.
Abnormal droppings may appear: more liquid, more abundant, or of unusual color.
In young birds, growth retardation and slower development compared to other chicks from the same clutch may be seen.
With heavy infestations, worms may sometimes be visible in the droppings.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
The disease is caused by the presence of roundworms (nematodes) in the digestive tract, mainly ascarids and capillaries.
Birds become infected by ingesting parasite eggs present in a contaminated environment: cage bedding, feeders, drinking water, or aviary substrate contaminated with droppings.
Some eggs can survive for long periods in the external environment, especially in a damp and poorly cleaned environment.
Living in dense groups, in poorly cleaned cages or aviaries, significantly increases the risk of infestation.
Young birds, whose natural defences are still developing, are more susceptible.
Contact with newly introduced birds without an observation period, or with droppings from wild birds, also promotes infestation.
Stress (transport, breeding, moulting) can worsen the disease in a bird already carrying parasites.
Transmission
Transmission occurs by the oral route, when the bird ingests parasite eggs present in an environment contaminated by infected droppings.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
The veterinarian makes the diagnosis by examining the droppings under a microscope, called a faecal examination, to look for parasite eggs.
Several samples may be needed, as egg shedding is not always regular.
A full clinical examination of the bird and its general condition always accompanies this diagnosis.
Treatment
Treatment is based on administering an antiparasitic medication suitable for birds, prescribed and dosed exclusively by a veterinarian.
Nutritional support and a clean environment often accompany the treatment to promote the bird's recovery.
Faecal checks after treatment verify the effectiveness and elimination of parasites.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Regularly cleaning and disinfecting the cage, food bowls, water bowls and aviary floor greatly reduces the risk.
Preventing the build-up of droppings in contact with the beak or food is essential.
Quarantining any new bird before introducing it into an existing aviary makes it possible to detect any parasitic infection before contaminating the group.
Regular veterinary checks of droppings, especially in breeding situations, help detect infestation before visible signs appear.
Possible complications
Severe untreated infestation can lead to severe weight loss, dehydration and general weakening of the bird.
In young birds or those already in poor health, infestation can favour other diseases by weakening natural defences.
In severe cases, intestinal obstruction from a large number of worms remains possible, although rare.
When to see a veterinarian
The bird is losing weight despite appearing to eat normally.
The plumage becomes dull, ruffled and the bird remains inactive.
Droppings become abnormal for a sustained period (watery, abundant, change in colour).
Worms are visible in the droppings.
A young bird grows noticeably slower than others from its clutch.
Several birds in the same group show similar signs at the same time.
Prognosis
The outlook is generally good when the parasitic infection is detected and treated early, with the bird making a complete recovery.
Without treatment, the bird's general condition may gradually worsen, especially in young or already weakened birds, which worsens the outlook.
Frequently asked questions
Can my canary transmit these worms to me or my other animals?
These roundworms are specific to birds and are not transmitted to humans or domestic mammals. However, they can easily spread to other birds living in the same space.
How can I tell if my canary has worms without taking it to the vet?
There is no certain sign you can identify at home. Only a microscopic examination of droppings, performed by a veterinarian, can confirm the presence of parasites.
Should all birds in the aviary be treated if only one is infested?
It's often recommended because other birds in the same space were likely exposed to the same parasite eggs, even if they're not yet showing signs.
Can this disease be prevented without medication?
Good cage and aviary hygiene, with regular cleaning and preventing birds from contact with their own droppings, considerably reduces the risk, even if it does not eliminate it entirely.
References
ESCCAP — European Scientific Counsel Companion Animal Parasites
WSAVA — World Small Animal Veterinary Association
Content reviewed by the TunisieVet editorial team · Updated 19 August 2026
Comments (0)
No comments yet.
AT A GLANCE
Need a veterinarian?
Find a practitioner near you on TunisieVet, with their specialities, hours and contact details.
Find a veterinarianCategories
Affected species
This information is provided for educational purposes only and is not a substitute for a veterinary consultation. If you have any concerns about your animal's health, consult a veterinarian.
Thinking of welcoming a pet? Dogs and cats are waiting for a family in Tunisia, and adoption is completely free.
Adoption listingsTo discover
Related diseases and linked Animalia content.
Canary respiratory acariasis (sternostomosis)
Parasitic
Canary pox virus
Viral · Vaccine available
Avian megabacteriosis (Macrorhabdus ornithogaster)
Fungal
