Why do tests need to be done on my bird?
Birds are very good at hiding illness. Veterinarians use test results in conjunction with physical examination findings and the owner’s account of the bird’s history to diagnose illness. Veterinarians may recommend certain tests for further insight into the bird's problem or for early detection of various diseases. This assists 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, inapparent problems.
"Wellness testing is done routinely on apparently healthy birds to screen a bird for possible subclinical or low-grade problems."
Blood can be collected in many ways from a bird. Your veterinarian will use one of your bird's blood vessels, typically on the bird’s neck, 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 upon the bird’s weight.
What tests can be done on a bird?
Complete blood count (CBC). CBC is 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 percentages 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 a commonly used disease screening test in birds. Certain blood parasites may also be detected during this test.
Chemistry profile. From the serum (fluid portion) of the blood sample, several tests can be run to assess the health status of the bird. Numerous enzymes and products of metabolism can be evaluated. Function of different organs, such as the liver and kidney, can be assessed, as well as the levels of blood glucose (sugar), protein, and electrolytes.
Gram's stain. This is a commonly used, quick diagnostic tool that is also used to monitor the progress of a patient during treatment. A variety of samples are routinely tested, including the feces, and aspirated (with a small needle) samples of swellings or growths on the bird’s body. These specimens are carefully 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 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.
Further testing to culture and identify the bacteria may be important for treatment.
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 are collected using special sterile cotton swabs.
The swabs are then sent to a laboratory. The laboratory 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 agents (pathogens) and determine the antibiotics (in the case of bacteria) or anti-fungal drugs (in the case of fungi, such as yeast) that will work against the organism and also determine those that will have no affect (those to which the organisms are resistant to). 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, and 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 and Giardia, are visible only under a microscope. Your veterinarian will examine samples taken from a fecal floatation or feces directly smeared on microscope slides (fecal direct smear testing). These tests identify parasites and their eggs and allow your veterinarian to treat your bird with the proper anti-parasitic drugs.
Urinalysis. The urine is the clear liquid part of a bird's droppings (as opposed to the white solid uric acid portion or the brownish green stool), and under most normal circumstances, there will be little urine to evaluate, as birds typically conserve water and secrete solid urine waste as uric acid. With certain diseases, a bird may pass enough urine that your veterinarian can carefully collect it to assess its cellular and biochemical components. Certain diseases can be detected from urine analysis; however, urinalysis may not be as accurate or useful in birds as it is in cats, dogs, and other mammals because bird’s urine is mixed so closely with their stool that it may be impossible to separate for testing.
X-rays. X-rays provide invaluable information in birds regarding internal structures such as bones, vital organs, and the respiratory system. X-rays also help assess for the presence of internal masses or growths, as well as ingested foreign objects. Changes in density, size, shape, and relative position of organs and tissues are assessed with X-rays. Some birds may need an anesthetic to safely obtain diagnostic quality X-rays, especially if they are very stressed with handling.
Laparoscopy. Surgical laparoscopy is the process by which specialized fiberoptic endoscopes are used in an anesthetized bird to examine the interior of certain body cavities and organs. Organs can be viewed and biopsied through just a small incision in the bird, and crucial information can 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.
Histology. 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 will specifically identify the disease process present and may provide information useful for prognosis.
Virology. Blood and other tissue samples can be tested to detect the presence of particular viruses and to determine the underlying cause of 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 psittacine beak and feather disease, polyoma, Chlamydophila, Pacheco's disease, and aspergillosis.
Sexing is also commonly performed in birds by DNA testing.
Post-mortem testing (necropsy). Despite all efforts and care, not all patients can be saved. When an animal dies, the final diagnostic procedure 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 helps to determine the 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 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.