Testing and Diagnostics for Sick Pet Birds

By Gregory Rich, DVM; Laurie Hess, DVM; Rick Axelson, DVM

Why do tests need to be done on my bird?

As a prey species, birds are programmed to not show signs of weakness or disease. Hence, birds are very good at hiding symptoms of illness. Veterinarians use diagnostic testing in conjunction with a thorough physical examination and the owner’s account of the bird’s history to help diagnose the cause of the patient’s illness.

Veterinarians may recommend specific tests for further insight into the bird's problem or for early detection of various diseases. Documentation of a disease process aids in the speedy diagnosis and timely treatment of an ailment. Diagnostic tests are also used to evaluate or monitor the progress a patient is making during treatment of disease or illness. Wellness testing is done routinely on apparently healthy birds to screen for possible underlying, hidden problems.

Blood can be collected from a bird in many ways. Your veterinarian will use one of your bird's blood vessels, typically on the bird’s neck (jugular vein), leg, or wing, to safely and easily obtain the sample needed with little stress to the bird. Only a small amount of blood is needed in most cases, and the amount the veterinarian draws is based on the bird’s weight. In general, 10% of the bird’s body weight consists of blood. A veterinarian can safely take 10% of the patient’s blood for sampling and testing. So 1 mL can be safely taken from a 100-gram bird, if needed. Most blood analyzers only need 0.5 mL of blood, serum, or plasma to run a blood profile.

What tests can be done on a bird?

Complete blood count:  A complete blood count (CBC) provides a measure of the total number of red blood cells, white blood cells, and platelets. It also involves an in-depth evaluation of the red blood cells and the five types of white blood cells. Different diseases may affect the number, shape, structure, and percentage of the various types of blood cells in a bird. A great deal of information may be obtained from this test about the health status of a bird, so it is commonly used for disease screening in birds. Certain blood parasites may also be detected during this test. Low red blood cell counts are indicative of anemia. Elevated white blood cell counts are indicative of either an infectious or an inflammatory disease process.

Chemistry profile: Several tests can be run on the serum or plasma (fluid portion) of the blood sample to assess the health status of the bird. Numerous enzymes and products of metabolism can be evaluated. Function of the liver and kidney can be assessed, as well as the levels of blood glucose (sugar), protein, calcium, phosphorus, and electrolytes.

Gram's stain: This quick diagnostic tool is commonly used to monitor the progress of a patient during treatment. A variety of samples are routinely tested, including the feces and samples of swellings or growths on the bird’s body (aspirated with a small needle). These specimens are mounted on a microscope slide and treated with a series of special stains. Veterinary staff examine the stained slides under a microscope.

Gram’s stain is also used to detect the presence or absence of bacteria and yeast in bird’s crop fluid or stool. Bacteria are identified along with their shape, size, and number. Since certain types of bacteria occur naturally in your bird’s stool, your veterinarian will determine whether the organisms in your bird’s gram-stained sample are normal or abnormal and whether treatment is needed.

A bacterial culture may be submitted to specifically identify what bacteria are present and if treatment is warranted.

Culture and sensitivity: Bacteria and fungi (including yeast) play an important role in many diseases in birds. Samples from the digestive tract, reproductive tract, respiratory system, eyes, nose, ears, skin, wounds, and any other body tissues may be collected using special sterile cotton swabs. The swabs are then sent to a laboratory, which takes the sample and attempts to grow, isolate, and specifically identify any disease-causing organisms (bacteria or fungi).

The next step is to test these disease-causing organisms (pathogens) and determine which antibiotics (in the case of bacteria) or anti-fungal drugs (in the case of fungi, such as yeast) will be effective and which drugs will have no effect (those to which the organisms are resistant). This test takes several days, but its results allow your veterinarian to treat your pet bird with the correct antibiotic.

Parasite testing: In birds, parasites may be found externally on the skin or feathers or internally in the digestive tract, respiratory tract, or blood or circulatory system. Veterinarians use various techniques to diagnose parasite infections. Mites and lice may be seen with the naked eye or may require microscopic analysis of samples from skin scrapings. Intestinal parasites, such as roundworms, capillaria and Giardia, are visible only by microscopic analysis of the fecal material. Your veterinarian will examine fecal samples by performing a fecal floatation or a fresh warm saline preparation. These tests help identify intestinal parasites and/or their eggs and allow your veterinarian to prescribe the proper anti-parasitic treatment for your bird.

Urinalysis: The urine is the clear liquid part of a bird's droppings (as opposed to the solid, white, uric acid portion or the brownish-green fecal portion),

X-rays (radiographs): X-rays provide invaluable information about the patient’s internal structures such as bones, vital organs, and the respiratory system. X-rays also help assess for the presence of masses or growths inside the body cavity, as well as ingested foreign objects. Changes in density, size, shape, and relative position of organs and tissues are assessed with X-rays. Most birds require a sedative or gas anesthesia to safely obtain high quality diagnostic X-rays. 
(Bird X-ray photo courtesy of Gregory Rich, DVM)

Laparoscopy: Surgical laparoscopy is a process in which specialized fiber-optic endoscopes are used in an anesthetized bird to examine the interior of certain body cavities and organs. Internal organs can be viewed and biopsied through just a small incision, about the size of a pencil lead in the bird abdomen, allowing crucial information to be obtained with minimal invasiveness.

Cytology: A commonly used technique to collect tissue or fluid samples is called fine need aspiration (FNA). FNA involves taking a small needle with a syringe and suctioning a sample of cells or fluids directly from a growth, tumor, other tissues or organs and placing them on a microscope slide. The cells are treated with a series of special stains and then your veterinarian or a veterinary pathologist examines the slide under a microscope to classify the types of cells present and designate them as normal or abnormal.

Histopathology: Samples of biopsied tissue, tumors, or growths removed surgically are sent to a laboratory where a veterinary pathologist will examine them under the microscope. These highly trained veterinarians identify the specific disease process present and may provide information useful for prognosis and/or treatment.

Virology: Blood and other tissue samples can be tested to detect the presence of viral organisms and to determine whether these viruses are the cause of the clinical disease.

Genetic tests (PCR testing): Various blood and tissue sample tests are available to detect the presence of genetic material (including DNA and RNA) of organisms that cause many significant diseases in birds including avian bornavirus, psittacine beak and feather disease (PBFD), polyomavirus, chlamydia, Pacheco's disease, and aspergillosis.

Sex identification is also commonly performed in birds by DNA testing.

Necropsy (post-mortem testing): Despite all efforts and care, not all patients survive treatment. When an animal dies, one of the most critical diagnostic procedures is the post-mortem examination or necropsy. It is best performed as close to the time of death as possible, as the bird’s tissues degrade after death and results of their analysis become less helpful after they have degraded.

During a post-mortem examination, your veterinarian collects tissue samples for a veterinary pathologist to examine microscopically. This examination helps to determine what organs were diseased and, hopefully, the specific cause of death. Post-mortem examination results are particularly important if the deceased bird lives with other birds. From necropsy findings, important decisions may be made regarding treatment of other birds in the same house. Much is learned from this examination that may even help other birds with the same ailment in the future.

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