Avian PCR

Biobest provides specialist avian sexing and diagnosis services to bird owners and veterinary surgeons.


Biobest offer a range of DNA testing options which can be performed on many difference species of birds.  This includes avian sexing to accurately determine a bird's sex and diagnostic testing for chlamydia, PBFD, polyomavirus and pigeon circovirus. Please refer to our avian sample submission instructions and submission form which can be found here.

Unfortunately we cannot accept samples from overseas.

Advice on the interpretation of our results is always available from our veterinary surgeons.


Avian Sexing

The sexing PCR detects DNA sequences in the avian sex chromosomes. Cock birds are ZZ, and hen birds ZW. We have developed three slightly different methods based on this difference, which allow us to test most species of birds successfully.


Psittacine Beak and Feather Disease PBFD

Psittacine beak and feather disease (PBFD) is caused by a circovirus. It has a wide species range, although it appears to be a natural viral infection of cockatoos in Australasia where it occurs in wild flocks; a related virus can cause disease in pigeons and doves.

The PBFD virus is extremely infectious. It can be passed through a colony of birds in two ways: ingestion of inhalation from infected material, such as faeces, feather dust, crop secretions or infected surfaces, or by vertical transmission from hen to egg embryo.

The symptoms vary depending on which form of disease the bird has. In acute cases the main action of the disease is to destroy the cells of the beak, feather and immune system. This causes abnormal feather loss and replacement feathers to be malformed, with lesions on the feather shaft.


Avian Chlamydia

Avian chlamydiosis is a reportable, acute or chronic infectious disease of certain poultry, cage, wild and migratory birds. The disease is zoonotic and can affect people severely, various disease syndromes are seen in humans from mild flu-like signs through severe respiratory problems, hepatitis and even death in the elderly. In Psittacidae (parrots, parakeets, cockatoos etc) and humans the disease is called psittacosis. In other bird species it may be referred to as ornithosis.

We use PCR to detect DNA from Chlamydia psittaci. The nature of psittacosis is such that affected birds that are relatively well do not shed the organism every day. Taking pooled samples (rice grain amounts) into one sample container daily over 3 days improves detection.  Always discuss the testing strategy with your avian veterinarian.


Avian Polyomavirus

Avian polyomavirus (APV) was first discovered in budgies and was called Budgerigar Fledgling disease, although it has since been discovered that most species of psittacine birds are susceptible to infection.


Pigeon Circovirus

Pigeon circovirus (PiCV) infections have been reported worldwide. A broad range of clinical signs are associated with this virus, including lethargy, anorexia, weight loss, reduced race performance, respiratory distress and diarrhoea. Definitive diagnosis has to date relied on histopathology. Examination of infected young birds reveals the presence of characteristic inclusions in lymphoid tissue such as the bursa of Fabricius. As this organ shrinks in size as birds grow older and is tiny or absent in adult birds, diagnosis by histopathology alone is unreliable.

PCR detects the presence or absence of the viral genome, and can assist the diagnosis of PiCV disease at post mortem. We have validated this test using liver samples and gut contents from pigeon and non-pigeon species, and have shown there is a link between strong positive PCR results and clinical signs compatible with PiCV related disease. In addition, positive PCR results and positive histopathology results were shown to be correlated. Negative PCR results can rule out the involvement of PiCV infection in sick pigeons.

This test may be performed on samples of the liver and gut contents.



Avian Sampling Videos

To help avian customers with taking samples. We have produced two videos that explain how to take and submit swab and feather samples.

Avian Sample Type Guidelines

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Please Note

Sexing - On occasion it can be difficult to extract quality DNA from mouth swabs

Chlamydia - There is no published data confirming that blood gives comparable results to faeces or tissue for chlamydia

Pigeon Circovirus - There is limited validation on sample types other than tissue at PM


Egg Membrane

Carefully scrape the membrane from the inside of the egg (or take a small section of the egg with the membrane attached) and place in a labelled container or sealable freezer bag. Please refrain from sending the whole egg or crushing the egg and membrane into tiny pieces. If storing samples for a few days before sending a batch, please allow the membrane to dry out before placing in container/bag, to prevent DNA degradation.

Mouth Swab

Ensure the bird has no food in its mouth; if necessary, rinse with water. Use only mouth swabs provided by Biobest – Please contact us. Remove swab from the tube (keep the lid attached) and rub the inside of the bird’s cheek, on both sides, firmly for at least 10 seconds. Allow the swab to air dry for a few seconds. Place swab in the tube and push down the lid to close the tube. Pull the swab handle firmly away from the tube leaving the swab pad inside the tube. Close plug to seal tube. Label the tube clearly with the bird’s reference.

It is possible to successfully extract DNA from egg membranes, feathers and blood in over 99% of samples. However it is harder to extract DNA from mouth swabs, not due to a test issue but due to sampling procedure, such that the successful extraction rate is about 60%. To maximise the chances of extraction success, please follow the sampling instructions very carefully and for mouth swabs read the additional information sheet.


Pluck at least three feathers and place them in a labelled container or sealable freezer bag. Feathers should have follicle cells attached to them therefore mature chest feathers which come out easily are not the best to use. Newly emerging larger feathers are preferable as they contain feather pulp in their shafts. Clipped or moulted feathers cannot be tested. Please do not pluck primary, secondary or tail feathers.


It is advisable to use your veterinary surgeon for blood sampling in order to reduce the risk of contamination. If this is not possible blood can be collected by clipping the bird’s toe nail however special tubes are required which contain heparin to prevent the blood clotting. About 50µl is required for all tests and one sample is enough to run any or all of the tests. If in doubt please consult your vet or consider an alternative sampling method.

Taking blood from birds which are sick or have poor clotting can be dangerous. If in doubt please consult your vet.


Collect a small amount of fresh droppings and place in a labelled rigid leakproof container. A pooled sample, i.e. a small amount of ‘rice-grain’ droppings collected over 3-5 days, will provide optimum sensitivity. Larger volumes of one sample will not increase the chances of a positive result.  It is not recommended to send samples from multiple birds as this will decrease the test sensitivity.

Cloacal Swabs & Tissue Samples

These sample types should only be taken by a vet.


Please take care when collecting samples from more than one bird to avoid cross-contamination between samples. Use fresh instruments and disposable gloves for each sample. Taking blood from birds which are sick or have poor clotting can be dangerous. If in doubt please consult your vet.


What do my test results mean?

Avian Sexing

The sexing report will state whether the sample was found to contain male or female DNA.

Chlamydia PCR

Positive: Bird is shedding chlamydia and may be clinically ill or an asymptomatic carrier. Risk to owner as potential zoonosis.

Negative: Chlamydia not detected in that sample. This does not prove bird is free from chlamydia, and if there is any doubt further samples should be taken at regular intervals.


Positive: Bird is suffering from an acute or chronic PBFDV infection. If the bird is showing typical clinical signs the diagnosis of PBFD is confirmed and the prognosis is poor. If the bird is healthy it should be re-tested after 2 months to confirm whether the infection was transient or the bird is a chronic carrier and dangerous to other birds. Contact with other birds should be avoided during this period.

Negative: No evidence that the bird is suffering from PBFD or is a carrier. If clinical signs are typical of PBFD then the possibility of poor quality sample should be considered and a repeat sample submitted.

Polyomavirus PCR

Positive: Bird is infected with polyomavirus. Not all birds infected with the virus develop clinical disease, so a positive test result must be interpreted in association with the clinical findings

Negative: No evidence that the bird is suffering from Polyomavirus. As for PBFD if clinical signs are typical of polyomavirus disease, the possibility of a poor quality sample should be considered.